Dr. Rajesh Ramayan  "Raj" Koothrappali, Ph.D., is an astrophysicist and Howard Wolowitz's best friend. He often hangs out at Leonard and Sheldon's apartment, though he has his own apartment (the Raj Mahal) in Pasadena. Raj fell in love with while attending Cambridge University . Originally from New Delhi, Raj has an Indian English accent and, ironically, dislikes Indian food and culture. He frequently portrays himself as having come from humble origins and growing up in poverty in India, only for his friends to remind him that his father is a gynecologist, drives a Bentley, and has a house full of servants. For the first six seasons, his principal characteristic was a case of selective mutism social anxiety disorder, which did not allow him to talk to women outside of his family. This condition could be suppressed through alcohol (or if he thought he was drinking alcohol) or experimental social anxiety medications; however, the former usually ended up changing his personality, making him more obnoxious and overbearing, while the latter tended to have unpredictable side-effects.
Rajesh Koothrappali was born in New Delhi, India on October 6, 1981 to Dr. V.M. Koothrappali and Mrs. Koothrappali. At the age of 5 he discovered a celestial object which later turned out to be the moon. He also has a younger sister Priya and also 3 brothers and 1 other sister. While growing up in India, he didn't really like it there and grew to dislike his country's food and culture. Later, Raj left India and attended Cambridge University, England in the United Kingdom. While speaking to his then-girlfriend Lucy, he stated that he thought Cambridge University looked like Hogwarts. After graduating with a degree in Astrophysics, he moved to Pasadena, California There, he met Howard Wolowitz who became his best friend and Howard's mother made Raj feel welcome into their house. (Although she thought he was the gardener for two years.)
Raj and Howard meet Leonard and Sheldon's new neighbor, Penny, who quickly learns of Raj's inability to speak to women (unless they're in his family). Halfway through the season, everyone discovers that Raj can actually talk to a woman by being drunk or on drugs, as evidenced when Penny gives him a cocktail while going through bar tending training.
Raj is upset when Leonard starts a relationship with his sister while she's in town. At the end of the season, Raj and Penny become closer friends, up to the point where they allegedly have a one-night stand.
In the end Raj gets over his selective mutism and is now able to talk to all women ("The Bon Voyage Reaction").
Raj begins a relationship with a dermatologist, Emily Sweeney.
Raj meets a screenwriter and bartender named Claire, and gets involved in a love triangle with her and Emily.
Dr. Rajesh Koothrappali is an astrophysicist and faculty member in Caltech's Physics Department. He was part of the team to launch the New Horizons space probe to collect data about the Pluto system and beyond. For his discovery of a planetary object beyond the Kuiper belt, 2008 NQ17 (which he calls "Planet Bollywood"), he is included in People magazine's "30 Under 30 to Watch", granting him some form of celebrity status and a larger office for his work. He is also known for a publication on Kuiper belt object size distribution, having run a simulation to correct for the observational efficiency, and was awarded the Newcomb Medal. His research even extends to searching for Trojan asteroids at the Earth-Sun L5 Lagrange point and he wrote a paper on the Van Allen belts. However, the work Raj performs at the university is repetitive enough that he could conceivably be replaced by a simple software program, and he fails to observe an exoplanet orbiting the star Epsilon Eridani with his much anticipated time using a ground-based telescope operating in Hawaii.
During "The Pirate Solution", when Raj's research testing the predicted composition of trans-Neptunian objects ends, his working permit and visa are bound to become void, as they are only valid as long as he is employed. He seeks out a research position in stellar evolution with Professor Laughlin. However, the job proposition fails as the research team includes an attractive female, Dr. Catherine Millstone, and Raj accidentally drinks a little too much alcohol, causing him to make a sexually explicit comment. To avoid Raj's deportation to India, Sheldon asks him to work for him and, after several disputes, he agrees.
Wanting to be the male "Indira Gandhi of particle astrophysics (but with a penis of course)," Raj researches dark matter. With Sheldon, he explores the string theory implications of gamma rays from dark matter annihilations and considers methods of optimizing a detector for 500 GeV particles to look for the annihilation spectrum resulting from dark matter collisions in space. While Sheldon argues that slow-moving xenon doesn't produce ultra-violet light, Raj posits that xenon can emit the tell-tale ultra-violet light from dark matter collisions, potentially negating a series of dark matter discoveries, and points to neutron scattering data.
Originally from India, Raj is slightly clueless about American culture and idioms, and dislikes Indian food and his home country. Sheldon even disputes his knowledge of Indian customs and Hinduism, and reveals Raj's native language is English, while he seems to speak fluent Hindi. Raj stated that the reason he puts up with Sheldon is so that he could be reborn as a "well-hung billionaire with wings", according to his Hindu belief of being rewarded after reincarnation for suffering willingly; to Raj, karma is "practically Newtonian". He hates Indian music; however, he does appreciate the Indian lullabies his mother sang to him, and the catchiness of Hindi phrases, two mentioned phrases being "जो जी करे कर" - "whatever floats your boat;" and "Fever 104, बहुत अच्छे संगीत का मौजूदा घर. The phrase means: Fever 104, home of the really good current music."
On the rare occasions when he actually gets homesick, he picks up the latest issue of "Bombay Badonkadonks" and performs Bollywood dancing. He is hypocritically sensitive to others' racist jokes about India, though he is not above making derogatory remarks about India, or, in his view, "Gandhi-ville". Raj also claims he can hold out from noxious gases because he grew up in India. Raj likes to say that he comes from the "exotic" subcontinent of India and had to overcome poverty and prejudice, to make himself appear interesting and mystical, especially when he is womanizing. More often than not, he likes to be associated with Slumdog Millionaire, except when Howard's mother says it. Much like how Howard rarely follows kosher, Rajesh eats beef and believes that some of the Hindu Code of Manu is crazy.
Raj also has an extremely ambiguous attitude and opinion of his own country and upbringing, which primarily depends on the situation he finds himself in and how it would benefit him. He believes that his most flattering quality for women is not an aspect of his own character, but the fact that he has vastly rich parents. As stated before, he enjoys portraying himself as a child of poverty who heroically journeyed to America to reach for the stars, but what puts him at the opposite end of this spectrum is his rich parentage. He portrayed himself as such because it makes him appear heroic. Rajesh also tends to heavily rely on his family's wealth for his own lifestyle, often wielding the family fortunes extravagantly. He enjoys his privileged lifestyle to such an extent that, when he wanted something off his father he offered to cut off the cleaning lady so that he could provide for himself, then muttering to Cinnamon that 'they were both going to be living like animals'.
He used to have a psychological condition called selective mutism, a recognized social anxiety disorder which rendered him unable to talk to women (with the exception of family members, who were seemingly unaware of his condition, and deaf women, as seen in "The Wiggly Finger Catalyst" when he could talk in front of Emily), although he quickly learned that he was able to temporarily overcome this problem by consuming either alcohol-containing foods and medicine or experimental anti-anxiety medication. Unfortunately, the alcohol altered his personality and the medications tended to have side effects, such as involuntary face and hand motions, loss of rationality, or jovially stripping naked in public without cognizance of its inappropriate nature. Raj was also able to speak in the presence of women if they were part of a crowd, if he was unaware of their presence, or if he believed that he has been drinking alcohol (a placebo effect, as seen in "The Terminator Decoupling" when he was able to talk to Summer Glau while drinking beer, but when Howard pointed out that the beer was non-alcoholic, he could no longer speak to her). Raj noted, however, that this obstacle was an improvement over his previous affliction, in which the presence of women would cause him to lose bladder control, a condition mostly remedied by the meditation methods of ancient Indian gurus. (He does still have a "nervous bladder" in the sense that he gets an urge to relieve himself when under stress.) When Lucy broke up with him In the season six finale, "The Bon Voyage Reaction," he discovered while talking to Penny that he was... well, talking to Penny, even though he had not consumed any alcohol since the previous night, which made him realize that breaking things off with Lucy seemed to allowed him to finally overcome his selective mutism. As of season 7, he no longer requires alcohol in order to speak in front of females.
One of Raj's primary personality quirks beside his selective mutism is his tendency to speak or act inappropriately in most situations. One primary example of the latter was when, in "The Love Car Displacement", he enters Leonard and Penny's room while they are about to have sex, climbs into bed and goes to sleep, completely unaware of what he interrupted. On another occasion, he openly acknowledged having had crushes on Penny and Bernadette directly in front of them, simultaneously making them uncomfortable and making Amy upset, and fails to recognize Amy's change in mood despite Penny and Bernadette's discreet efforts to indicate it to him. Seen in "The Santa Simulation".
He complains that he is lonely, which leads to Raj hating himself and needing to be reassured of his value. While usually sweet, Raj sometimes smiles at his friends' misfortunes. Whenever Raj gets an idea or wants to say something slightly controversial in a conversation, he whispers it in Howard or someone else's ear whenever a woman is around. Howard does refuse to say it out loud because he finds it stupid, offensive, or inappropriate, but he ends up saying it anyway through scoffing at Raj. He also has arguments with Howard often, being akin to those of a married couple. He is noted for using "gangsta" slang, such as "fo' shizzle" and repeatedly using the word "dude".He enjoys reading DC Comics, as do his friends, but he dislikes Aquaman. Raj often obsesses over almost-insignificant details in fiction, such as how toilets work in Atlantis, the possible symbolism of ponytails in Avatar, whether Wolverine's prostate is made of adamantium, what zombies would eat if humanity was exterminated, how vampires would shave themselves since they can't see their reflections, etc. He has experienced gaming addiction and, like Howard, he idolizes Stephen Hawking. Unlike the other guys, Raj has shown great interest in some non-geeky things likes John Grisham novels and Archie comics, the latter being shared with Zack. Raj also has an interest in a number of books and TV shows which are generally targeted towards the female demographic, such as Twilight, The Good Wife, Grey's Anatomy, Sex and the City, Eat, Pray, Love, and Bridget Jones's Diary.
Raj is 5' 7" (1.70 m), with black hair and brown eyes. He is normally seen wearing a layered combination of a shirt, a sweater vest, and a windbreaker with cargo pants and skate shoes; he wore a red baseball cap in the Pilot.
- Grandfather: Dilip Koothrappali
- Parents: Dr. V. M. (father) and Mrs. Koothrappali (mother)
- Sisters: Priya Koothrappali and an unnamed sister
- Brothers: 3 unnamed brothers
- Cousins: Venkatesh Koothrappali and Sanjay Koothrappali
- Uncle: Unnamed uncle
Raj always communicates with his parents, Dr. V.M. and Mrs. Koothrappali back in India over Skype, via webcam. They constantly try to arrange dates for him. Raj's parents want their son to marry a woman of Indian descent and give them grandchildren. Mrs. Koothrappali is especially worried that despite Raj being old enough to marry, the closest they have to a daughter-in-law is "that Jewish boy," Howard. When they become meddling or judgmental, he often "brings his parents" into Leonard and Sheldon's apartment via his MacBook Pro, to seek his friends' support in the discussion. Like his "baby sister" Priya, whom he is very protective of, Raj calls his parents "mummy" and "daddy".Despite Raj's claims that he grew up in poverty, his friends like to remind him that he comes from a very wealthy background. His father is a gynecologist, drives a Bentley (he also owns a Mercedes, which was later burnt by his mother), and has a house full of servants, two of them children. Raj later admits this fact, saying they are very wealthy. His parents say the same thing, believing they have nothing to complain about as they are very rich in a very poor country. In "The Wiggly Finger Catalyst", it is revealed that his parents are actually billionaires, as Sheldon claims that Raj's family's estimated wealth is 'halfway between Bruce Wayne and Scrooge McDuck', a reference to Forbes: The Fictional 15.[This quote is seen in "The Wiggly Finger Catalyst"].
Not much of Raj's family is known so far. Raj stated he has three brothers and two sisters in "The Hot Troll Deviation" (S4E04). One older brother is mentioned in "The Cornhusker Vortex" (S3E06) who, according to Raj, gave him his 'Patang' (fighter kite). And one of his two sisters is Priya.
Raj's cousin Sanjay Koothrappali (aka "Dave") works in a Call Center run by AT&T. In "The Guitarist Amplification", Raj tried to avoid going to his wedding, but eventually accepted his parents' offer.
Another cousin, Venkatesh (who appeared in "The Precious Fragmentation"), works as a lawyer in Mumbai. He has poor negotiation skills, even admitting that he is useless when Raj was trying to negotiate for a jet ski.
In "The Griffin Equivalency", Rajesh points out that his limo is bigger than the house that his grandfather grew up in and has more food too, suggesting that his family was not always wealthy. In "The Table Polarization" (S7E16), he reveals the name of his grandfather to be Dalib.
In "The Alien Parasite Hypothesis", Raj mentions that Type 2 diabetes runs in his family, but he has no symptoms so far.
In "The Septum Deviation", Raj is worried about what to get his parents for their fortieth wedding anniversary. Later he gets a call from his father that he has moved out and that his parents are getting divorce lawyers. It seems over the years they did not communicate and let a lot of little things boil over until they hated each other. His mother may have also been seeing someone else.
In "The Clean Room Infiltration", Raj's father is in the middle of a divorce and visits his son at Christmas time. Raj leaves to help his friends deal with a stray pigeon and his father is left with Amy and Penny and her boring Victorian parlor games.
In "The Graduation Transmission" , Raj's father threatens to cut him off after he too much on a toy helicopter. After flattering both parents, Raj ends up with a huge increase in allowance from both his divorced parents.
Leonard and Raj meet at the University in "The Staircase Implementation". Made clear in "The Jerusalem Duality", both Raj and Howard like Leonard. Though, Raj takes delight in Leonard's problems with Penny and becomes somewhat adversarial with him when he dates his sister, Priya. Despite his tendency to tease Leonard about his girlfriend issues, he is supportive of his and Penny's relationship and frequently attempts to get him to break up with Priya (sometimes employing subtle manipulative techniques, such as feeding his paranoia about the two women comparing notes about his sex life). Raj feels jealous when Leonard and Howard use his ideas for fun and exclude him. Raj has said that Leonard only hangs out with him if he has no other options, and has missed him ("The Spaghetti Catalyst"). When Sheldon and Penny were indisposed, Leonard took the very appreciative Raj with him to Switzerland for a visit to the Large Hadron Collider after both Penny and Sheldon fall sick [as seen in "The Large Hadron Collision". They normally try to help each other. In "The Date Night Variable", Raj hangs out with Leonard and Penny on their date and gets thrown out when he tries to get Penny to tell Leonard that she loves him. In "The Cooper Extraction", Amy points out to the gang that most of them would not know each other if Sheldon had not been part of their lives. Since Leonard is not in Apartment 4A, Raj envisions them living together, however Leonard is fat due to Raj's cooking and Leonard's loneliness.
Generally, Raj is much more patient with Sheldon than Leonard, Howard and Penny- although this fact is partly because Sheldon does not criticize him quite as often as the others. When asked, he mentions it is because of his belief in Karma. Sheldon, however, appears oblivious, as he once tried to cut off Raj from his circle of friends to make room for Barry Kripke and because Raj got one answer for his questionnaire wrong. Raj was terrified at the prospect of losing Sheldon as a friend, and later worries whether he is merely the "treasured acquaintance." Sheldon hates it when Raj is talking in his ear, although he does appreciate Raj's words. Whenever Raj is upset, Sheldon brings him a hot beverage to console him, although this act is because his mother would make him. In "The Roommate Transmogrification", Raj proves to be a better roommate to Sheldon than Leonard was, as he goes out of his way to impress him. Considering Raj a good friend, Sheldon enjoys the ethnic diversity he brings about in the group and the fact that he too likes monkeys and trains. In the episode "The Pirate Solution", when Raj's research hits a dead end, Sheldon offers Raj a chance to work for him, which he later accepts. Since then, Raj has been working for Sheldon, and they occasionally clash. Raj maintains that he does not work for Sheldon, but with him and Sheldon agrees on the opposite, making Raj as the person who works for/with Sheldon. They also have a nerd war over the overly large desk Raj moved into his office- although Raj at first seems to be winning, their attempts to one-up one another eventually cause the office to explode. This action is seen in "The Hot Troll Deviation".Howard is Raj's best friend; since Season 1, they have always been very close and met about the same time they were introduced to Leonard and Sheldon. Raj usually comes to Howard's house for holidays such as Thanksgiving, and has sometimes slept over there, as well. He knows all of Howard's jokes and finds humor in mimicking Mrs. Wolowitz. Rajesh is sometimes sensitive to Howard's cultural stereotyping as well as his perceived inability to recognize when he is upset. They are practically inseparable, maintaining certain weekly routines together and serving as wingmen to each other. Although Raj and Howard are heterosexual, their relationship and interaction sometimes resembles that of a couple, which resulted in Leonard's mother, Beverly Hofstadter, calling their relationship an "ersatz homosexual marriage". As seen The Maternal Congruence and The Maternal Capitance despite the denials, Raj amusingly still takes up a stereotypical "female" role in arguments with Howard, for example, accusing him of deserting him for any opportunity to speak with an attractive woman. During Howard's launch in The Countdown Reflection, both he and Howard's wife Bernadette express their love for Howard and hold hands. It's been mentioned in "The Septum Deviation" that Howard and Raj attend couples therapy together. Howard invents a game where he quotes Raj and others have to guess if the comment is about the dog he loves or the woman he loves (Emily) due to his attachment to Cinnamon. In "The Anxiety Optimization", Howard starts a game called "Emily or Cinammon" where people have to guess whether statements Raj has made are for the woman or the dog he loves. Emily thinks Raj's sensitive nature is very sexy. In "The 2003 Approximation", Raj and Howard form a band call "Footprints on the Moon", when Stuart is looking for live music in his store. They write a song about Indiana Jones taking on Thor which is a cool song, but not easy to dance to.
Penny is the closest female friend that Raj has, though he has only been able to talk to her when drunk. Penny sometimes tries to make Raj speak, but mostly feels sorry for him, such as by calling him a strange little man, damaged, and even kissing him on the cheek, while Raj believes her to be considerate of him. There are times where his relationship with Penny becomes less than platonic - particularly in "The Griffin Equivalency", where he misinterprets her going with him to an award ceremony as an act of romance rather than friendship and introduces Penny to his parents as his "new squeeze" while he was drunk. He tried to apologize by note, but Penny forced him to say the apology while sober. In "The Roommate Transmogrification", Raj and Penny hooked up while they were drunk, and, while they were leaving the bedroom, ran into Howard, Leonard, and Sheldon. In "The Skank Reflex Analysis", Raj reveals to Penny that they did not have sex or any physical activity instead, Raj ejaculated prematurely when Penny tried to help him put on his protection and then they fell asleep. Raj asks Penny not to tell anyone about this incident, to which Penny agrees. They accept to go back to being just friends. She agreed that he could tell others that "their light shone too quickly and brightly", but couldn't tell people that he "ruined her for white guys". In "The Wiggly Finger Catalyst", Penny sets him up with a deaf friend of hers that can communicate with him by signing. In "The Santa Simulation", Penny invites him along to a girls' night out and they try and find him a girl although nothing works out. She wants to find him a girlfriend, but twice her attempts fail.
Raj's relationship with Bernadette is somewhat strained, because of him having secret feelings of her and fantasizing about Howard leaving and he needing to fulfill her sexual needs. When Penny starts a false rumor that Bernadette is breaking up with Howard, Raj begins to awkwardly hit on her at the Cheesecake Factory (after drinking a grasshopper). When Howard proposes to her, Raj is the only one to encourage him to propose, as they all knew the result. However, when Bernadette accepts his proposal, Raj is crushed. In the season 5 premiere Bernadette is angry because she learns that Raj had feeling for her, expressed through inappropriately worded poems(Oh Bernadette, please play my clarinet.) She learns this from Howard, who himself learned of it during an argument with Raj and Leonard earlier that day over his allegedly sexual encounter with Penny, where Leonard accused Raj of falling in love with any girl who smiled at him, using Bernadette as an example(to Howard's shock). Leonard had himself learned of this in the previous season from Priya. A lot of what Raj does Bernadette finds creepy.Amy has not been properly explored yet, but they are shown to be friends and she can find it weird that he can't talk to women. After Sheldon invites the lonely Raj on his and Amy's anniversary date, she tells him to go home. In "The Santa Simulation", he tells Amy that he was never interested in her like his crush on Penny and Bernadette. She then draws him out that they both missed the company of the opposite sex. They talk about their humiliations while growing up until Raj says that he hopes that the girl he finds is as half as much a lovely person as Amy. Amy then says that he wants me, I'm good. She says that they can leave now, obviously getting back at Raj. Then Raj tells Penny on the way out that now he may fall for Amy. At Amy's suggestion, Raj invites her to dinner with him and Lucy as the first in the gang to hang out with her. Things go fine until Amy mentions Lucy's social problems and Raj pushes her too much. Amy also asks Raj at Leonard's going away party, where Lucy is showing concern for him. She is the only friend that calls him Rajesh instead of Raj. In "The Friendship Turbulence", Raj asks Amy to respond to a girl that answered Raj's dating site. Though the girl thinks that Raj is too shy and passive, she does strike up a friendship with Amy. After Raj charges in on their coffee get-together, Raj ruins a possible friendship for both of them.
Beginning with the "The Date Night Variable", Raj became closer friends with Stuart since Howard was away on the ISS. They go out to bars looking for ladies and do other things Raj and Howard used to do. Stuart moved in with Raj to get out of the back of the comic book store. They held parties at the comic book stores together (for Halloween and Valentine's Day) and Stuart let Raj borrow the store for the scavenger hunt in "The Scavenger Vortex". The two of them try to help each other find dates, such as with online dating ("The Raiders Minimization") and trying to talk to women together at malls ("The Hesitation Ramification"). It is unknown when and why Stuart moved out of Raj's apartment, but they still hang out together, usually at Raj's place. In "The Mommy Observation", Stuart helped Raj plan another murder mystery night. When Stuart's store (and current "home" again) burns down in "The Status Quo Combustion", Raj said he could live with him again for a while, but due to Emily staying with him that night, Stuart ended up living at Mrs. Wolowitz's house, working as her care-giver for a while. In "The Comic Book Store Regeneration", Raj helped Stuart get the new comic book store ready for opening.
Unlike the other main characters, Raj's romantic relationships have never been very serious or lasting, mostly due to his inability to speak to women. He has had a number of one-night-stands and brief dates. Impressively though, Raj was the first one among the four to get laid within the series in "The Middle Earth Paradigm" at Penny's Halloween party. He is much more successful in casual sex than the more sexually aggressive Howard, and, among the guys, has great appeal to extremely attractive women. He has/had a big crush on Howard's fiancee (now wife), Bernadette Rostenkowski, who has said how wonderful a man he is and has called him a "cutie pie", much like Penny. At one point, Raj implies that he is dating a "deaf chick" before he ever meets Penny's deaf friend Emily, though later admitted this to be a lie.
One of Raj's female childhood acquaintances, Lalita Gupta used to be fat. She also kicked him in the samosas (testicles) and called him untouchable. In spite of this fact, Raj's parents thought it would be a good idea to set them up on a date. Raj discovered that alcohol (grasshopper cocktail) is able to help him suppress his selective mutism, but being drunk made him obnoxious. As a result: he generally weirded out Lalita. Sheldon, because of Lalita's resemblance to a beloved childhood fairy tale character, Princess Panchali, unintentionally "stole" Lalita from Raj causing him to get angry with Sheldon.
In "The Pork Chop Indeterminacy", Sheldon's fraternal twin sister, Missy, came to Pasadena. Raj at the time was using an experimental drug to help with his selective mutism. Leonard, Howard and Raj were all attracted to her and after hitting on her too much (causing her to hide at Penny's for the night) and fighting over the "right" to ask her out, they decide to just ask her out individually. After both Leonard and Howard's attempts failed, Raj got his turn. Inconveniently, as he waited for her at Penny's door, the drugs began wearing off and despite Missy's implied interest in Raj, (saying "Hi, cutie pie. I was hoping you'd show up") Raj was unable to ask her out and walked away.
In "The Terminator Decoupling", when Sheldon, Leonard, Howard, and Raj were on a train to San Francisco, the latter three tried talking to sci-fi actress Summer Glau. After drinking what he thought was a beer, Raj talked to Summer, being flirtatious and smooth and she took a liking to him. He said Slumdog Millionaire was based off of his life story and revealed his knowledge of astronomy. When Howard pointed out that his beer was non-alcoholic, Raj stopped in the middle of his conversation, was embarrassed and rushed away from Summer without saying any more.The Psychic Vortex", Leonard and Howard went on a double date with their respective girlfriends, leaving a lonely Raj with only an indifferent Sheldon. Raj insists on Sheldon helping him score with a girl at a University Mixer. After presenting Sheldon with a "Limited Edition Green Lantern Lantern" and his "Incredible Hulk Hands signed by Stan Lee" on two separate occasions, Sheldon agreed to be Raj's wing-man, helping him score with Abby. It is not known what happened to her after that episode.
In "The Plimpton Stimulation", Dr. Plimpton was welcomed as a guest of Sheldon's for a few days while considering taking a position at the University. Incredibly promiscuous, she shows interest in Raj immediately after meeting him despite having slept with Leonard the previous night and sitting next to him at the time. That evening, Raj was hosting Dr. Plimpton, but when Leonard and Howard show up, she immediately suggests they join Raj and her. Raj directs his friends so they can leave and spends the night with Dr. Plimpton.
Angela (Tiffany Dupont)
Rajesh and Sheldon met Angela at a coffee shop while Raj was trying to test an experimental social anxiety drug. Raj told her she was very beautiful when she asked why he was staring, and flattered, she liked his accent, stating she was interested in going to India. As she welcomed him sitting with her, Raj introduced them as Dr. Rajesh Koothrappali and Dr. Sheldon Cooper, scientists who like to observe, and dismissed Sheldon off to buy a scone. Koothrappali complemented her name, citing its etymology, to which she responded he was cute. However, a side effect of the medication caused him to begin stripping, which scared her away, while he told Sheldon he was being rude and attempted to continue with her saying she had the expressive face of an actress.
In "The Wiggly Finger Catalyst", Penny thought she found the perfect match for Raj by hooking him up with a woman who is deaf, Emily. Raj made very obnoxious remarks during their first date, but translator Howard would sign something else to Emily as to make him not look like a jerk. Raj and Emily saw each other for a month with Raj getting very attached to her, however, it turns out she liked Raj only for his money and left him when she found out his parents would cut their financial support if they continued to see each other. Interestingly, his parents did not cut him off when he was seeing the white dermatologist, Emily Sweeney in the seven and eight seasons.
After Raj buys a new iPhone 4S in the "The Beta Test Initiation", he develops a peculiar relationship with his phone's voice command personal assistant, Siri. Contrary to his usual inability to speak to women directly, Raj is able to address her, as she is a mere voice. Whenever Raj inquires about an activity he wishes to engage in or a destination, she provides suggestions (like a wine selection for a dinner party) or a list of possible locales, of which a subset is emphasized due to proximity. In reaction to Raj, Siri is able to accept compliments, respond to inquiries about her well-being, and display emotions, like gratitude. Upon Raj's request to be called "sexy", Siri complies and Raj, in turn, refers to her as "darling". Raj appears to be actually dating Siri by taking her places, having human conversations with her and buying her gifts. However, Raj has a dream that he goes to meet Siri in the form of a real woman, but, of course, when she turns around, he can't speak to her. Thus, an offer to make love to her is unable to be fulfilled. He then wakes up screaming "NOOOOO!"
In "The Tangible Affection Proof", Raj and Stuart put together a Valentine's Day party for those who do not have dates. Raj figures that their group should not keep beating themselves up and he makes a speech that they shouldn't measure their self-worth by whether they are in a relationship and that they are not alone because together they are a community. Lucy walks up to Raj to tell him that his speech was really cool. They leave to have coffee together.
The next episode "The Monster Isolation" picks up with them having coffee. Raj explains more about himself when Lucy excuses herself to the Bathroom. While Raj gets more Chai Tea Lucy is seen escaping through the bathroom window from the shop and running away. Raj is next seen a few days later by Leonard and Howard after he fails to show up at work. He is upset because Lucy ditched him and proclaims he's never leaving his apartment. Rajesh's apartment is a mess and he is ordering his food on line. Later the guys run into Lucy at the comic book shop as she left off a note for Raj. Howard calls her out for her ditching him and takes the note with her phone number. Howard later gives Raj her number and the two agree to meet. Lucy reveals that she has anxiety issues. Pushing her to meet people she shows up at the Valentine's Day Party after seeing a flyer explaining that she doesn't even like comic books. To make her more comfortable Raj explains his own anxiety with women and his inability to talk to them without alcohol. He proclaims he's just as messed up as her and begs her for a chance to prove it. The two agree to go out on another date.
At Penny's, Raj seeks advice on a killer first date with Lucy. Amy says that evolutionary biology shows that women like men that are steady in the face of danger and suggests an unsafe environment. Raj mentions that Lucy has some social anxieties and wants something simpler. Bernadette suggests Disneyland's Space Mountain ride where you can hold hands in the dark though Raj doesn't think Lucy would like the crowds. After the girls get excited to go to Disneyland themselves, they can't come up with any other helpful suggestions.
Later Raj sets a table at a library with picnic paraphernalia for his date with Lucy. She arrives and asks if they are eating there. Raj texts her that they are having a "texting date". She replies that she likes the idea. He also tells her to remember that he has an adorable accent. They have a good time laughing at each other's comments. Lucy tells him that she does web design for porn sites. Raj denies even knowing what it is but, due to an auto-correct error, she says she really works on prom sites. Raj texts back he really likes proms, but when Lucy looks at him funny, he texts that it was auto-correct and that it should be that he likes sports. Lucy and Raj finish their date when her phone battery runs out. She says she had fun and that this date definitely pushed her comfort envelope. Lucy flees with a panic attack when she tries to kiss Raj. Raj says he is still counting it as foreplay.
In "The Closure Alternative", Raj finds Lucy's blog saying that she is seeing a man named Roger who she finds a bit feminine. Howard clues him in that she is using a fake name to protect his identity after Raj thinks she is seeing someone else. At dinner, he wears a hockey shirt, nukes a half-cooked meal and gives Lucy a lecture on monster trucks to be more masculine. His behavior freaks her out so Raj admits that he found her blog. Lucy meant that he was kind and sensitive which made Raj feel better.In "The Love Spell Potential" at an awkward date, though they all seem a bit awkward, Lucy is describing areas where she is trying to push herself. On their next dinner date, Lucy says that her crab cakes are a bit funky and Raj tries to get her to send them back, one of her areas where she is trying to push herself. She again runs away, climbs out the bathroom window and then finds herself in a locked fenced in area. She then texts Raj who finds her there. Raj tells her that even though she has all these quirks, he finds that very attractive since she is more broken than he is. Through the fence, the two of them kiss.
In "The Bon Voyage Reaction", Raj wants Lucy to hang out with his friends. Lucy is reluctant, but agrees wit meet with one. First, Raj asks Leonard, until Penny suggests maybe in of the ladies should do it. Penny and Bernadette are too pretty and might be threatening to Lucy, so Amy suggests that it should be her since she was the outsider of the group. At dinner, she was talking about her experiences with the gang and everything is going well until Raj again starts to push her. Raj tells Lucy that she doesn't have to if she doesn't want to. Amy replies that they should ignore him since he doesn't realize that she understands the severity of Lucy's social anxiety. Raj objects to her talking to somebody about social anxiety if they have a social anxiety which makes them society anxious, Amy then gets annoyed and tells him that she is a neurobiologist and that she is more qualified to know what is not working in his girlfriend's brain. Amy is also talking to Raj as if Lucy is not even there. Raj reacts that she is not his girlfriend although he immediately asks Lucy if she could be. Lucy is getting more uncomfortable when Raj adds that if she says no, he will never be happy again. Lucy runs off to the bathroom. Raj tells Amy that they might as well eat since she is not coming back soon. Later agrees to come to Leonard's going away party after Raj begs her to come. At the party, Lucy is late and then texts him that she isn't coming. Also, she tells him that maybe they shouldn't see each other again and they break up which really upsets Raj. Later we learn that his experience with Lucy has helped him get around his selective mutism as he finds he can talk to Penny.
In "The Itchy Brain Simulation", Penny meets Lucy at the Cheesecake Factory and yells at her for breaking up with him by email. She also tells her that Raj was devastated and that she was a bad person. Lucy then asks to have coffee with Raj and apologizes how she broke up with him. Raj hopes that they can get back together; however, she is now seeing somebody.
In "The Hofstadter Insufficiency", Raj goes to a work social to finally try and meet women and runs into the recently separated Janine Davis. First, he insults her, and then after a rough apology, they sit down and have an adult conversation as friends, something new for Raj. After she leaves, he still brags to Howard that he wants more, but admits that he'll probably not follow up on it.
In "The Locomotive Manipulation", while under the care of Leonard and Penny , Cinnamon eats a box of Valentine's candy which can make a dog quite ill. When Raj reaches the vet's office, he is very angry with Leonard and Penny and very protective of his dog. This statement touches the vet who also owns a dog. On the instructions she gives Raj, she also gives him her phone number.
In "The Friendship Turbulence", Emily answers Raj's dating site and Raj has Amy answer for him. Emily finds Raj too shy and passive, but has a lot in common with Amy so they plan to get together. Raj charges in trying to not be passive, but Emily finds him weird and without any boundaries and leaves. Raj has ruined a possible friendship for both him and Amy.
In "The Relationship Diremption", Raj and Emily have dinner with the Wolowitzes. Howard recognizes her because he was set up on a blind date with Emily sometime near 2009 before he met Bernadette. He had a bad stomach and had to go to the bathroom and clogged the toilet, he was too embarrassed to tell her so ran out through the window. They meet again at dinner where she is now dating Raj. Emily reveals she's okay with it and her friends love the story. They call him "Clogzilla".
In "The Anything Can Happen Recurrence", Raj and Howard watch the gore-fest "House of 1000 Corpses" because Emily wants to watch it with Raj. They are both turned off and wonder about someone who likes this type of movie. On their date, Raj tells Emily how he feels about it and she also wonders about someone who likes this film. She also admits that it turns her on, so Raj immediately starts it so they can watch it.
In "The Gorilla Dissolution" Raj finds Emily at the movies with another guy. Later she visits him to talk. The guy was her tattoo artist who had been asking her out for weeks and she did so just to end the obligation. She mentions the tattoo on her shoulder, one that is not on her shoulder and one that is REALLY not on her shoulder. It has been a long time since Raj has seen something REALLY not on someone's shoulder. Emily suggests that if he'll show her his pierced belly button, he can see all her tattoos. They start to kiss and she then spends the night.
In "The Hook-up Reverberation", Penny meets Emily for the first time and she seems cools to her. At Bernadette's suggestion, Penny stops by Emily's office to do her sales pitch in front of a real doctor. Penny does her pitch enthusiastically, however, Emily ignores her. She doesn't like that Penny had crawled into bed with Raj. Though Penny is mad as Raj, he gets then together and they apologize to each other. After they part, both women say how much they hate the other one
In "The Prom Equivalency", Raj takes Emily to the re-do prom thrown by Bernadette and Amy. She shows off her Sally (from "Nightmare Before Christmas") tattoo on her and weirds-out Bernadette adding some horror trivia to her favorite Cinderella fairy tale. She also tells Raj that she is having a good time watching the drama between Howard and Stuart over him bringing his second cousin Jeanie whom Howard lost his innocence to.
In "The Anxiety Optimization", Howard starts a game called "Emily or Cinnamon" where people have to guess whether statements Raj has made are for the woman he loves or the dog he loves. Emily thinks Raj's sensitive nature is very sexy.
In "The Intimacy Acceleration", Emily gets the gang to go to an escape room where puzzles have to be solved to exit the room. The genius get out in six minutes.
In "The Colonization Application, Raj snoops around Emily's apartment when he is alone and breaks her bed bureau. Emily is not happy, but forgives him. She gets back when she tells him it's good that he didn't look in her closet, causing Raj to wonder what was in it.
In "The Commitment Determination", Raj confides in Howard and Bernadette how different he is from Emily and that he is considering breakup with her. Howard doesn't believe that he will break up with a girl that has sex with him. At a grave yard picnic, Emily picks up on these vibes and tells Raj that he has to break them up and not make her do it. Instead, Raj tells her that he was just trying to say that the loves her and kisses her, not knowing her reaction.
In "The Valentino Submergence", Raj breaks up with Emily so he can ask Claire out. That doesn't go well and Emily won't take him back. Raj has been wondering about their relationship for several episodes.
In "The Application Deterioration", Raj get calls from both Emily and Claire. Emily just wants to talk. Claire advises him that she is just manipulating him. He ends up at Emily's to just talk because she is so upset, but they end up in bed. Raj remarks, "Good talk."
Claire is a writer for a children's science fiction series whom Raj meets at the comic book store in "The Meemaw Materialization" and wants to collaborate with Raj the science portions of a movie script. She is only interested in his help while Raj has visions of marriage and children. In the following episode "The Valentino Submergence", Raj breaks up with Emily Sweeney. Later, he finds out that Claire just got back together with her boyfriend, and she considers Raj an ass for breaking up with Emily right before Valentine's Day.
In "The Application Deterioration", Claire calls Raj back to tell him that she and her boyfriend broke up again, but he also gets a call from Emily and he is now torn between the two. Claire tells Raj that Emily is manipulating him and luring him there, but she backs away, telling Raj it's his life and he ends up in bed with Emily.
In "The Fermentation Bifurcation", Raj claims to be dating two women and Claire is seen going to a wine tasting with him and the gang, excluding Sheldon and Bernadette. He doesn't want them to ask too many questions since their relationship is casual. Claire gets hit on by Penny's old boyfriend Zack whom Raj stops when he tells him that they are together. Claire jokes about Raj seeing others and it's Raj that exclaims he is seeing someone else.
- Raj is 34 years old. He was born on October 6, 1981.
- Raj was the only one of the four (Howard, Leonard, himself and Sheldon) who had a present father figure until Leonard's father made his first appearance, so it is now Raj and Leonard of the four who have a present father figure. Howard's father has only been mentioned and Sheldon's died shortly before the start of the series, but Raj sees his father with his mother through his webcam.
- He has a Ph.D. in Astrophysics.
- The baseball cap Raj wears in the Pilot bears the number 42 (the answer to life, the universe, and everything) on it.
- Raj is 5 ft 7 in (1.70 m) tall  – the height of Kunal Nayyar. This measurement is two-and-a-half inches below the average height for males in the U.S. and two inches above the average height for males in India. In "The Transporter Malfunction", he states that, next to Howard and Bernadette, he looks 6 ft 2 in (1.88 m) tall.
- He lives in an apartment, which he calls his "Raj Mahal".
- Raj is not at all serious about his Hindu faith and eats beef, which is frowned upon by most Hindus.
- Raj calls his skin tone "Melt-In-Your-Mouth Caramel".
- Raj, much like Howard, despises many of Sheldon's antics, and the two managed to get Sheldon on a date with Amy Farrah Fowler on a dating website in "The Lunar Excitation", much to Sheldon's dismay.
- Raj's case of selective mutism was first evident in the Pilot episode.
- "Rajesh" is a common given name in southern India; however Raj claims that he is from New Delhi, suggesting either that his family moved from their native area, or ignorance on the part of the creators. His surname, "Koothrappali", however is unheard of.
- Whenever Raj gets an idea or wants to say something slightly controversial in a conversation, he whispers it in Howard's ear if a woman is around. Howard never wants to say it out loud because he finds it stupid or offensive, but he ends up saying it anyway through scoffing Raj. Sheldon hates him talking in his ear altogether, although he does appreciate Raj's words.
- Raj says that he "struggles with Batman,"
- He regularly communicates with his parents (V. M. Koothrappali and Mrs. Koothrappali) back in India via webcam. When they become meddling or judgmental, he often "brings his parents" into Leonard and Sheldon's Apartment 4A via his MacBook Pro, to seek his friends' support in the discussion.
- He has a mug that says 'World's Best Astrophysicist'. It was given to him by Sheldon.
- His father is a gynecologist and drives a Bentley.
- Raj shares his interest in monkeys with Amy and trains with Sheldon.
- Rajesh often has married-couple-like arguments with Wolowitz and, when nervous, often whispers into his ear leaving him to translate to everyone else.
- As with Wolowitz, the others in his circle of friends often refer to him by his surname. He frequently wears a purple jacket and a sweater vest.
- Rajesh's selective mutism even applies in dreams. Most notable is with Siri. ("The Beta Test Initiation").
- Rajesh performs vocals when playing Rock Band (albeit extremely badly), which could possibly be a joke because he suffers from selective mutism. Though in a Season 2 promotional photo, he is playing with a guitar controller, so he is either playing the bass or the lead.
- He despises Guitar Hero because he feels it is lame, though he still plays it.
- Raj is considered the attractive one of the group because women find him foreign and exotic, plus his selective mutism makes him a very "good listener."
- He worked with/for Sheldon.
- He has been featured in People Magazine ("30 Under 30 to Watch!").
- He has a MySpace account.
- In seasons 1 - 6, he has problems talking to women unless he is drunk. In "The Porkchop Indeterminacy", he tried an experimental medication for his problem, but stopped taking it because of the side effects. In "The Wildebeest Implementation", he tried another medication he got from a friend at Caltech's school of pharmacology, but gave up on it too because it removed his inhibitions to the point that he stripped naked in the middle of a coffee shop.
- Unlike the other guys, Raj has shown great interest in some non-geeky and sometimes feminine things, such as Grey's Anatomy, The Good Wife, Sex and the City, Eat Pray Love, Bridget Jones' Diary and John Grisham's novels. He also likes Archie comics along with Zack and likes Twilight.
- Raj is addicted to internet pornography.
- He dislikes Aquaman, as he is always chosen to dress as Aquaman when they have a costume competition.
- Raj often obsesses over almost-insignificant details in fiction, such as how toilets in Atlantis in Aquaman work, the possible symbolism of ponytails in Avatar, whether Wolverine's prostate is made of adamantium, what zombies would eat if humanity were exterminated, how vampires would shave themselves if they can't see their reflections, etc.
- English is his native language, though due to being from India, he speaks fluent Hindi.
- Raj doesn't need to be drunk to talk to women: he just has to think he is drunk (Placebo Effect), as shown in "The Terminator Decoupling".
- Raj takes Pilates classes and Aerobics and claims to, as a result, have "very well-trained abs".
- In one scene, when his parents arranged a blind date, he refused and Sheldon explains that Indian arranged marriages result in a peaceful bond. Raj then says "I know my own culture", leaving Sheldon silenced.
- In one episode, Sheldon joins Penny in jogging, and Howard tells Penny that Raj always watches her from his car with binoculars.
- Like the common nerd, Raj was bullied as a child. He once got a penis drawn on his forehead on his first day of cricket camp, with the testicles drawn around the eyes. One person who bullied him was Lalita Gupta, who used to kick him in the nuts and call him "untouchable." They dated as adults, where a drunk Raj insults her by saying she used to be so, so fat as a child.
- His favorite number is 5,318,008. The reason for that is that when entered in a calculator, turning the calculator upside-down will read "BOOBIES".
- Raj is terrified of bugs. As he is also afraid of women, Sheldon jokes that ladybugs must render him catatonic.
- He was angry when Leonard and Priya decided to date again which means he is overprotective towards his baby sister, and is worried how terribly this could affect the friendship he has with Leonard.
- He is a fan of country-pop singer Taylor Swift and bought a Jersey at her concert at the Staples Center.
- In "The Roommate Transmogrification", Raj had a drunken sexual encounter with Penny, which they both apparently regretted instantly. (It is later on revealed, in the premiere of Season 5, that it wasn't consummated.) This would later become the catalyst of conflict between Penny and Raj's girlfriend.
- It is revealed in two episodes during Season 4 and the Season 5 premiere that Raj has a huge crush on Bernadette.
- Sheldon revealed that Raj's family is not just rich, but is "Richie Rich" rich.
- He is afraid of spiders, which is revealed in "The Alien Parasite Hypothesis".
- Even though Raj does not adhere to Hindu dietary restrictions, he does take certain aspects of his religion seriously and has brought up Hindu gods more than once in a conversation.
- Raj's selective mutism doesn't seem to apply to his female family members such as his mother and his sister Priya.
- Raj is the group's "historian", being able to keep record of many actions - for instance, in "The Hawking Excitation", Raj was able to recount how many times Sheldon has begged in the past.
- Raj is addicted to pedicures.
- Raj has had one threesome in his life. It was with Howard and a 200 pound girl in a Sailor Moon costume during a trip to Comic-Con.
- According to Lakshmi, the girl Raj goes out on a date with in "The Transporter Malfunction", there is a rumor back in New Delhi that Raj is "comfortable in a sari" (i.e. he is gay).
- In "The Bakersfield Expedition", Raj dressed as the a Klingon from Star Trek: The Next Generation.
- Raj's drink of choice has remained the grasshopper since he was first served it in "The Grasshopper Experiment": he can be seen drinking one in numerous episodes thereafter.
- Raj owns a female Yorkshire Terrier named Cinnamon. She was given to him by Howard and Bernadette in "The Transporter Malfunction" to console him over his failed date with Lakshmi. Raj spoils Cinnamon terribly, feeding her elaborate home-cooked meals and pushing her around in a baby stroller.
- It is revealed that in "The Prestidigitation Approximation" that Raj keeps a Uhura costume on hand in his closet; a source of great shame for his family. "Leonard: Hypothetically, if I had access to a lieutenant Uhura uniform, would you wear it? Priya: Leonard, it is a source of great pain to me and my family that my brother has that outfit in his wardrobe."
- He, Bernadette and Leonard are the only characters of the social group whose parents have both been seen on-camera - Sheldon's father is deceased since Sheldon was a child, Howard's father abandoned him and his mother when Howard was eleven, and Penny's mother is mentioned, but there has still been no appearance or mention of Amy's father.
- Raj is the only member of the guys not to commit an illegal act or be arrested. Leonard nearly committed treason by nearly showing rocket fuel to Joyce Kim, and blew up the elevator by accident with his rocket fuel. Howard destroyed the Mars Rover, not to mention other illegal activities such as using government property for his personal use. Sheldon was thrown in jail for insulting a judge in traffic court, and has had several restraining orders filed against him by various celebrities (such as Stan Lee and Leonard Nimoy). In the Convention Conundrum, it was revealed that Raj fears being arrested out of fear of being deported back to India. However, Raj has had several incidents with Human Resources at the University.
- He drives a BMW with seat warmers.
- Regarding Bollywood actresses, Raj describes Aishwarya Rai as a "goddess" and prefers her over Madhuri Dixit.
- Raj, Leonard, Sheldon and Howard are the only characters of the current main cast who have appeared in every episode (not counting the Unaired Pilot).
- Raj may be an olfactophile which is shown in "The Gothowitz Deviation".
|He finally overcame his selective mutism in the season 6 finale "The Bon Voyage Reaction".|
|An image gallery is available for Raj|