The Big Bang Theory backdrop
Comedy

The Best Episodes of The Big Bang Theory Season 4

Every episode of The Big Bang Theory Season 4 ranked from best to worst. Discover the Best Episodes of The Big Bang Theory Season 4!

Binge this in 8h 17m•Peaking at 8.0/10

Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.

Airs on
CBS
BestEpisodes
WorstEpisodes
BestSeasons
AllEpisodes

Seasons12

All123456789101112

Episode Rankings

  1. #1 Fan Favorite
    The Big Bang Theory Season 4 Episode 1 - The Robotic Manipulation
    8.0/10(61 votes)

    #1 - The Robotic Manipulation

    S4:E1

    Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  2. The Big Bang Theory Season 4 Episode 2 - The Cruciferous Vegetable Amplification
    7.8/10(52 votes)

    #2 - The Cruciferous Vegetable Amplification

    S4:E2

    Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  3. The Big Bang Theory Season 4 Episode 3 - The Zazzy Substitution
    7.5/10(50 votes)

    #3 - The Zazzy Substitution

    S4:E3

    The guys are concerned as Sheldon searches for an alternative to human companionship.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  4. The Big Bang Theory Season 4 Episode 4 - The Hot Troll Deviation
    7.7/10(52 votes)

    #4 - The Hot Troll Deviation

    S4:E4

    An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  5. The Big Bang Theory Season 4 Episode 5 - The Desperation Emanation
    7.4/10(52 votes)

    #5 - The Desperation Emanation

    S4:E5

    Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  6. The Big Bang Theory Season 4 Episode 6 - The Irish Pub Formulation
    7.5/10(51 votes)

    #6 - The Irish Pub Formulation

    S4:E6

    Leonard keeps an affair a secret from Sheldon, Howard and Raj.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

    7. Trending NowTRENDING NOW

    The 20 BEST Episodes of The Big Bang Theory

    READ
  7. The Big Bang Theory Season 4 Episode 7 - The Apology Insufficiency
    7.6/10(48 votes)

    #7 - The Apology Insufficiency

    S4:E7

    Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  8. The Big Bang Theory Season 4 Episode 8 - The 21-Second Excitation
    7.8/10(46 votes)

    #8 - The 21-Second Excitation

    S4:E8

    While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  9. The Big Bang Theory Season 4 Episode 9 - The Boyfriend Complexity
    7.9/10(51 votes)

    #9 - The Boyfriend Complexity

    S4:E9

    Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  10. The Big Bang Theory Season 4 Episode 10 - The Alien Parasite Hypothesis
    7.4/10(47 votes)

    #10 - The Alien Parasite Hypothesis

    S4:E10

    Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  11. The Big Bang Theory Season 4 Episode 11 - The Justice League Recombination
    8.0/10(52 votes)

    #11 - The Justice League Recombination

    S4:E11

    The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  12. The Big Bang Theory Season 4 Episode 12 - The Bus Pants Utilization
    7.4/10(51 votes)

    #12 - The Bus Pants Utilization

    S4:E12

    Leonard's idea for a smartphone app derails his friendship with Sheldon.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  13. The Big Bang Theory Season 4 Episode 13 - The Love Car Displacement
    7.8/10(50 votes)

    #13 - The Love Car Displacement

    S4:E13

    Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.

    Director:Anthony Rich
    Writer:Unknown

    Be the first to start the conversation for this episode

  14. The Big Bang Theory Season 4 Episode 14 - The Thespian Catalyst
    7.6/10(48 votes)

    #14 - The Thespian Catalyst

    S4:E14

    Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  15. The Big Bang Theory Season 4 Episode 15 - The Benefactor Factor
    7.4/10(48 votes)

    #15 - The Benefactor Factor

    S4:E15

    A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  16. The Big Bang Theory Season 4 Episode 16 - The Cohabitation Formulation
    7.5/10(45 votes)

    #16 - The Cohabitation Formulation

    S4:E16

    As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  17. The Big Bang Theory Season 4 Episode 17 - The Toast Derivation
    7.7/10(47 votes)

    #17 - The Toast Derivation

    S4:E17

    Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  18. The Big Bang Theory Season 4 Episode 18 - The Prestidigitation Approximation
    7.6/10(48 votes)

    #18 - The Prestidigitation Approximation

    S4:E18

    Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  19. The Big Bang Theory Season 4 Episode 19 - The Zarnecki Incursion
    7.7/10(47 votes)

    #19 - The Zarnecki Incursion

    S4:E19

    Sheldon's online-game account is hacked by Todd Zarnecki, who then proceeds to steal all his items prompting the guys to go on a quest to retrieve them. Penny, Bernadette and Amy discuss how Penny groomed Leonard to be willing to try various things and more adventurous boyfriend... for some other woman — Priya.

    Director:Peter Chakos
    Writer:Unknown

    Be the first to start the conversation for this episode

  20. The Big Bang Theory Season 4 Episode 20 - The Herb Garden Germination
    7.9/10(49 votes)

    #20 - The Herb Garden Germination

    S4:E20

    Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  21. The Big Bang Theory Season 4 Episode 21 - The Agreement Dissection
    7.3/10(50 votes)

    #21 - The Agreement Dissection

    S4:E21

    When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges due to the agreement's vague wording, much to Sheldon's dismay. When the guys take advantage of Priya's skills in order to eat Greek food on pizza night, Sheldon goes to Penny, who invites him to a girls' night out with Amy and Bernadette, which Sheldon agrees to after Penny mentions that they may be talking trash about Priya. After the girls drink some cocktails, they decide to take Sheldon dancing, which Sheldon reluctantly goes along with. After dancing, Sheldon takes an intoxicated Amy back to her apartment and as well as talking about Priya, meets a monkey who is addicted to smoking cigarettes. Amy tells Sheldon not to give in to Priya's law skills, before kissing him and going to her bathroom to vomit.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  22. The Big Bang Theory Season 4 Episode 22 - The Wildebeest Implementation
    7.1/10(54 votes)

    #22 - The Wildebeest Implementation

    S4:E22

    Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

  23. The Big Bang Theory Season 4 Episode 23 - The Engagement Reaction
    7.6/10(48 votes)

    #23 - The Engagement Reaction

    S4:E23

    When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.

    Director:Howard Murray
    Writer:Unknown

    Be the first to start the conversation for this episode

  24. The Big Bang Theory Season 4 Episode 24 - The Roommate Transmogrification
    7.6/10(49 votes)

    #24 - The Roommate Transmogrification

    S4:E24

    When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.

    Director:Mark Cendrowski
    Writer:Unknown

    Be the first to start the conversation for this episode

Season 4 Ratings Summary

"The Robotic Manipulation" is the best rated episode of "The Big Bang Theory" season 4. It scored 8/10 based on 61 votes. Directed by Mark Cendrowski and written by Unknown, it aired on 9/23/2010. This episode is rated 0.2 points higher than the second-best, "The Cruciferous Vegetable Amplification".