第 5 季 共 24 集
播出时间：2011年9月23日
第 1 集 The Skank Reflex Analysis
播出时间：2011年9月23日
Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleeping with Raj while Sheldon becomes the leader of the paintball team.
第 2 集 The Infestation Hypothesis
播出时间：2011年9月23日
A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.
第 3 集 The Pulled Groin Extrapolation
播出时间：2011年9月30日
Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.
第 4 集 The Wiggly Finger Catalyst
播出时间：2011年10月7日
Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.
第 5 集 The Russian Rocket Reaction
播出时间：2011年10月14日
Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity.
第 6 集 The Rhinitis Revelation
播出时间：2011年10月21日
Sheldon's mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time with the rest of the gang, instead of catering to his every demand.
第 7 集 The Good Guy Fluctuation
播出时间：2011年10月28日
A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.
第 8 集 The Isolation Permutation
播出时间：2011年11月4日
Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.
第 9 集 The Ornithophobia Diffusion
播出时间：2011年11月11日
Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each others chances with perspective dates. Meanwhile, Sheldon enlists the help of Bernadette and Amy to overcome his fear of birds.
第 10 集 The Flaming Spittoon Acquisition
播出时间：2011年11月18日
When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relationship with Amy is going.
第 11 集 The Speckerman Recurrence
播出时间：2011年12月9日
Leonard must face his fears after being contacted by his high school tormentor.
第 12 集 The Shiny Trinket Maneuver
播出时间：2012年1月13日
Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard must come to grips with Bernadette's dislike of children.
第 13 集 The Recombination Hypothesis
播出时间：2012年1月20日
Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two, and the duo contemplates on their relationship.
第 14 集 The Beta Test Initiation
播出时间：2012年1月27日
Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a "woman" he can talk to without being drunk, in the form of Siri on his new phone. Meanwhile, Sheldon decides to start a YouTube series entitled "Sheldon Cooper presents Fun with Flags" with the help of Amy.
第 15 集 The Friendship Contraction
播出时间：2012年2月3日
Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to pick his astronaut nickname.
第 16 集 The Vacation Solution
播出时间：2012年2月10日
When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.
第 17 集 The Rothman Disintegration
播出时间：2012年2月17日
Penny is horrified when Amy gives her a gift: a huge, quite horrible painting of the two of them. With no good way to avoid displaying it, she only hangs it up when Amy is over. When Amy catches her taking the painting down, she's embarrassed and angry until Penny lies and says the gift made Bernadette jealous.<br />
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When the deranged Professor Rothman is forced to retire, both Sheldon and Kripke vie for his office. President Siebert refuses to resolve the dispute, so Leonard arranges a one-on-one basketball game to decide (since they're both equally bad at sports). Neither one can even make a single basket, so they end up deciding by seeing who can bounce the ball the highest. Sheldon wins; unfortunately, the office is not what he'd hoped for: the thermostat is located in the office of a professor going through the hot flashes of menopause (thus Sheldon is too cold), the mockingbird outside his window is off-key with the annoying windchimes, the perpetually naked Professor Rothman refuses to vacate, and the Geology Department upstairs makes too much noise. Finally, Sheldon gets his head stuck in the wall in an existing hole, after which Leonard takes his picture before he goes for help.
第 18 集 The Werewolf Transformation
播出时间：2012年2月24日
Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to reconsider wanting to go into space. Penny beats Leonard in chess, the first time she plays.
第 19 集 The Weekend Vortex
播出时间：2012年3月9日
Sheldon must choose between joining Amy at her aunt's birthday party or playing videogames all weekend with the guys.
第 20 集 The Transporter Malfunction
播出时间：2012年3月30日
Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be haunted by Mr. Spock. Meanwhile, Raj decides he has met the “Future Mrs. Koothrappali” after his parents set him up on a date.
第 21 集 The Hawking Excitation
播出时间：2012年4月6日
When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.
第 22 集 The Stag Convergence
播出时间：2012年4月27日
After the guys throw Howard a bachelor party, Bernadette reconsiders marrying him after learning about his sexual history.
第 23 集 The Launch Acceleration
播出时间：2012年5月4日
When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the wedding plans in jeopardy. Meanwhile, Leonard says something surprising to Penny in the bedroom.
第 24 集 The Countdown Reflection
播出时间：2012年5月11日
The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, causing the gang to scurry into overdrive in an effort to stage the wedding. NASA astronaut Mike Massimino has a cameo as himself.
