The Big Bang Theory Wiki

Season 5 of The Big Bang Theory returned to television in September 2011. The season ended in May 2012. In this season, Amy Farrah Fowler and Bernadette Rostenkowski become main characters with more screen time.

The season is mainly focused on Howard and Bernadette's wedding, the end of Leonard's long-distance relationship with Priya, Leonard and Penny experimenting in dating again, and Sheldon officially becomes Amy's boyfriend.


Main Cast

Recurring Cast

Guest Cast


Episode (Series) Episode (Season/Ep#) Title Original Air Date Directed By Description
88 501 The Skank Reflex Analysis September 22, 2011 Mark Cendrowski Penny is worried with how damaged her friendship with the guys will be in the aftermath of her one-night stand with Raj while Sheldon becomes the leader of the paintball team.
89 502 The Infestation Hypothesis September 22, 2011 Mark Cendrowski A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.
90 503 The Pulled Groin Extrapolation September 29, 2011 Mark Cendrowski Leonard accompanies Amy to a wedding. Meanwhile, Howard and Bernadette spend a weekend with Mrs. Wolowitz.
91 504 The Wiggly Finger Catalyst October 6, 2011 Mark Cendrowski Penny finds the perfect girl for Raj to date. Meanwhile, Sheldon uses Dungeons & Dragons dice to make life's trivial decisions.
92 505 The Russian Rocket Reaction October 13, 2011 Mark Cendrowski Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity.
93 506 The Rhinitis Revelation October 20, 2011 Howard Murray Sheldon competes with the gang for his mother's affection when she comes to visit.
94 507 The Good Guy Fluctuation October 27, 2011 Mark Cendrowski A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.
95 508 The Isolation Permutation November 3, 2011 Mark Cendrowski Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.
96 509 The Ornithophobia Diffusion November 10, 2011 Mark Cendrowski Sheldon tries to cure his phobia of birds, while Leonard and Penny experiment with hanging out alone.
97 510 The Flaming Spittoon Acquisition November 17, 2011 Mark Cendrowski When Stuart, from the comic book store, asks Amy out on a date, Sheldon becomes jealous and acts on their relationship.
98 511 The Speckerman Recurrence December 8, 2011 Anthony Rich Leonard confronts his fears when he is contacted by a bully who tormented him in high school.
99 512 The Shiny Trinket Maneuver January 12, 2012 Mark Cendrowski Howard and Bernadette deal with the possibility of ever having a child, while Sheldon and Amy encounter the first bump in their relationship.
100 513 The Recombination Hypothesis January 19, 2012 Mark Cendrowski Leonard decides to invite Penny out on a dinner date, hoping to rekindle their relationship.
101 514 The Beta Test Initiation January 26, 2012 Mark Cendrowski Leonard and Penny deal with the possibility of a reconciliation and Raj finally finds a "woman" that he can talk to without being drunk; the Siri in his new iPhone. Meanwhile, Amy helps Sheldon start a new YouTube series called "Sheldon Cooper presents Fun with Flags".
102 515 The Friendship Contraction February 2, 2012 Mark Cendrowski Tired of being more like Sheldon's chauffeur than his roommate, Leonard invokes Clause 209 of The Roommate Agreement that allows him to be only an acquaintance. Meanwhile, Howard has been chosen by NASA to go into space and tries to get a neat nickname.
103 516 The Vacation Solution February 9, 2012 Mark Cendrowski Forced to undergo his mandatory vacation by President Siebert, Sheldon decides to join Amy at her laboratory, only to find himself struggling to do things right. Meanwhile, Bernadette and Howard face the issue of signing a prenuptial agreement, at her father's insistence.
104 517 The Rothman Disintegration February 16, 2012 Mark Cendrowski Sheldon and Kripke engage in sporting activities to battle each other out in order to find the winner of who will get the newly vacated Robb Rothman's office. Meanwhile, Penny feels uncomfortable with Amy's friendship gift.
105 518 The Werewolf Transformation February 23, 2012 Mark Cendrowski Sheldon's world turns upside-down when his barber gets sick. Meanwhile, astronaut training gets Howard to rethink his decision to join the upcoming mission to space.
106 519 The Weekend Vortex March 8, 2012 Mark Cendrowski Leonard plans a marathon video game event for the gang the same weekend Amy wants Sheldon to go to her aunt's birthday party.
107 520 The Transporter Malfunction March 29, 2012 Mark Cendrowski Sheldon opens his mint-condition vintage Star Trek transporter -- a gift from Penny which he ends up breaking. Meanwhile, Raj asks his parents to set him up with someone.
108 521 The Hawking Excitation April 5, 2012 Mark Cendrowski When Howard gets the opportunity to work with Stephen Hawking, Sheldon will do whatever it takes to meet him.
109 522 The Stag Convergence April 26, 2012 Peter Chakos The guys organize a bachelor's party for Howard, which leads to the unraveling of Howard's secrets. Bernadette accidentally hears about them, threatening their impending nuptials.
110 523 The Launch Acceleration May 3, 2012 Mark Cendrowski Howard's launch date gets pushed up, coinciding on the same week as his wedding, putting him in a dilemma. Leonard endangers his relationship with Penny with a sudden proposal to her, and Sheldon finds himself developing feelings for Amy after a few gestures from her.
111 524 The Countdown Reflection May 10, 2012 Mark Cendrowski Howard and Bernadette decide to elope after their wedding is put off to enable Howard to join NASA's mission to the International Space Station.