Where to watch The Big Bang Theory Season 4
Stream now on HBO MaxHBO Max
Stream now on Apple TVApple TV
Rent or Buy
Get Fetch on Fetch TVFetch TV
Streaming not available
Watch 9Now on 9Now9Now
Free
Streaming availability data from JustWatch.
The Big Bang Theory Season 4 episodes
S04 E01
The Robotic Manipulation
21 mins · Thu, 23 Sep 2010
Penny tags along on Sheldon's first-ever date with a woman he's been texting for months. Meanwhile, Wolowitz finds a new use for a robotic arm.
S04 E02
The Cruciferous Vegetable Amplification
20 mins · Thu, 30 Sep 2010
Sheldon realises he won't live long enough to download his consciousness into a robot body, so he attempts to extend his life span. Meanwhile, the gang bump into Apple co-founder Steve Wozniak at The Cheesecake Factory.
S04 E03
The Zazzy Substitution
21 mins · Thu, 7 Oct 2010
The guys are concerned when Sheldon searches for an alternative to human companionship, after he and Amy break up. Can they help restore his faith in people?
S04 E04
The Hot Troll Deviation
19 mins · Thu, 14 Oct 2010
An embarrassing secret of Wolowitz's comes to light as he tries to win back his ex-girlfriend, Bernadette. Meanwhile, Sheldon and Raj have a small war at work.
S04 E05
The Desperation Emanation
20 mins · Thu, 21 Oct 2010
Leonard realises that he's the only one of the gang without a girlfriend, while Sheldon wants to get rid of his when she hatches a plan for him to meet her mother.
S04 E06
The Irish Pub Formulation
21 mins · Thu, 28 Oct 2010
Leonard attempts to keep his secret affair with Raj's sister Priya from all of his friends. Sheldon begins to develop an overly elaborate, complicated and convoluted cover story for him.
S04 E07
The Apology Insufficiency
21 mins · Thu, 4 Nov 2010
Leonard believes his problem with women stems from a lack of confidence and vows to be more self-assured around attractive women. Meanwhile, Wolowitz has a call from the FBI.
S04 E08
The 21-Second Excitation
19 mins · Thu, 11 Nov 2010
The gang are excited about a new screening of Indiana Jones and Raiders of the Lost Ark, because there are 21 seconds of additional footage being seen for the first time, and camp out to get tickets for the film.
S04 E09
The Boyfriend Complexity
21 mins · Thu, 18 Nov 2010
When Penny's dad comes to visit, Leonard discovers that she told her parents they were back together because they always had a soft spot for him.
S04 E10
The Alien Parasite Hypothesis
20 mins · Thu, 9 Dec 2010
Amy finds she has sexual feelings for Penny's ex-boyfriend Zack, while Koothrappali and Wolowitz try to prove who would be the better superhero.
S04 E11
The Justice League Recombination
20 mins · Thu, 16 Dec 2010
The guys slowly warm to Penny's new boyfriend Zack, and find a way to bond with him when they enter a fancy dress contest.
S04 E12
The Bus Pants Utilization
21 mins · Thu, 6 Jan 2011
Leonard's idea for a smartphone application derails his friendship with Sheldon as they fight for control of the project.
S04 E13
The Love Car Displacement
21 mins · Thu, 20 Jan 2011
Tensions run high when Bernadette runs into her hulk of an ex-boyfriend at a science conference. Threatened by Bernadette's ex-boyfriend, Wolowitz has an argument with Bernadette and causes chaos.
S04 E14
The Thespian Catalyst
21 mins · Thu, 3 Feb 2011
Sheldon agrees to take part in a short lecture series at the university, but worries that the students don't seem to like him. On Amy's advice, he asks Penny to give him acting lessons so that he can engage with his audience better.
S04 E15
The Benefactor Factor
20 mins · Thu, 10 Feb 2011
A wealthy benefactor at the university makes Leonard consider how far he's willing to go in the name of science.
S04 E16
The Cohabitation Formulation
20 mins · Thu, 17 Feb 2011
Wolowitz is torn between taking things to the next level with Bernadette and pleasing his mother. Meanwhile, Leonard rekindles his relationship with Raj's sister, Priya.
S04 E17
The Toast Derivation
21 mins · Thu, 24 Feb 2011
Sheldon gets a new group of friends when the gang start hanging out at Raj's more often, and he realises that it's actually Leonard who is the centre of their social group and not him.
S04 E18
The Prestidigitation Approximation
21 mins · Thu, 10 Mar 2011
Leonard must choose between new girlfriend Priya and his friendship with Penny, and Howard drives Sheldon crazy with a magic trick.
S04 E19
The Zarnecki Incursion
21 mins · Thu, 31 Mar 2011
Sheldon is totally distraught after someone has hacked into his 'World of Warcraft' account. Howard, Leonard and Raj try to help him find the culprit.
S04 E20
The Herb Garden Germination
21 mins · Thu, 7 Apr 2011
Sheldon and Amy experiment on their friends by spreading gossip, while Howard takes a big step in his relationship with Bernadette.
S04 E21
The Agreement Dissection
20 mins · Thu, 28 Apr 2011
Priya uses her legal nous to dissect the roommate agreement and put Sheldon in his place. Meanwhile, the girls take Sheldon dancing.
S04 E22
The Wildebeest Implementation
21 mins · Thu, 5 May 2011
Raj attempts to cure his anxiety about talking to women, while Penny uses Bernadette to spy on Leonard and his girlfriend.
S04 E23
The Engagement Reaction
19 mins · Thu, 12 May 2011
Howard finally tells him mum that he's engaged to Bernadette. Unfortunately, the news lands his mum in hospital.
S04 E24
The Roommate Transmogrification
21 mins · Thu, 19 May 2011
Bernadette receives her PhD and the gang begin to tease Wolowitz for being the only one among them who isn't a doctor. Meanwhile, Koothrappali becomes Sheldon's new flatmate after hearing Leonard and Priya engaging in a Star Trek bedroom fantasy.