Watch The Big Bang Theory Online – Full Episodes in HD

I’m not interested in caring about people. – Ron Swanson

Preview
1
S01E01
Pilot
In the series premiere, when Leonard and Sheldon meet Penny, Leonard isimmediately interested in her. But Sheldon feels his friend is chasing a dream he'll never catch.
24 September 2007
2
S01E02
The Big Bran Hypothesis
After Leonard tries to do a favor for Penny, Sheldon ruins the plan. Leonard volunteers to sign for a package, hoping to make a good impressionon Penny. However, when he involves his obsessive-compulsive roommate, Leonard sees his attempt at chivalry go horribly awry.
1 October 2007
3
S01E03
The Fuzzyboots Corollary
Leonard is depressed to learn that Penny is dating someone. As a result, encouraged by his friends and fellow scientists, Leonard actually summons the nerve to ask a woman out on a date. SARA GILBERT ("Roseanne") guest stars as Leslie.
8 October 2007
4
S01E04
The Luminous Fish Effect
After being fired from his job, Sheldon attempts to explore the "dreadful" life beyond physics. But his initial thrill of shopping with Penny devolves over time to him weaving ponchos as a shut-in, forcing Leonard to call on Sheldon's mother, Mary (LAURIE METCALF - "Roseanne").
15 October 2007
5
S01E05
The Hamburger Postulate
After sensing that his pursuit of Penny isn't going anywhere, Leonard agrees to an unexpected sexual encounter with fellow scientist Leslie Winkle (recurring guest star SARA GILBERT). The one-night stand throws Leonard and Sheldon deep into uncharted social waters.
22 October 2007
6
S01E06
The Middle Earth Paradigm
The socially stunted guys are nervous when Penny invites them to a party she's hosting. But they are ecstatic to find out that it's a Halloween party and enthusiastically don their respective nerdy costumes, which unfortunately fail to impress Penny's brutish ex-boyfriend. Afterwards, Koothrappali experiences the unexpected with a partygoer, Cheryl (ERIN ALLIN).
29 October 2007
7
S01E07
The Dumpling Paradox
When Wolowitz seduces Penny's friend and ends up sleeping with her in Penny's apartment, Penny sleeps on Leonard and Sheldon's couch. Meanwhile, with Wolowitz occupied, the guys discover that they are without a fourth member of their group. In desperation, they ask Penny to join one of their two-person Halo teams.
5 November 2007
8
S01E08
The Grasshopper Experiment
Koothrappali becomes overwhelmed when his parents arrange a blind date for him, but he discovers he actually can talk to a member of the opposite sex after a few drinks. However, complications arise when his beautiful date shows more interest in Sheldon.
12 November 2007
9
S01E09
The Cooper-Hofstadter Polarization
Sheldon and Leonard are invited to present their joint findings at a physics conference, but Sheldon refuses. Penny steps in to mediate, but this only deepens the rift between the two best friends.
1 January 2008
10
S01E10
The Loobenfeld Decay
After hearing Penny sing, Leonard lies to avoid seeing her perform. Sheldon goes one step further with a more elaborate lie, leading to the appearance of his nonexistent cousin. D.J. QUALLS ("Road Trip") guest stars.
1 January 2008
11
S01E11
The Pancake Batter Anomaly
When Sheldon gets sick, Leonard and the boys know what is in store for them and avoid him like the plague; this leaves an unsuspecting Penny to nurse the world's worst patient back to health.
1 January 2008
12
S01E12
The Jerusalem Duality
When Leonard and Sheldon meet a 15-year-old physics prodigy, Sheldon is distraught that this boy genius is younger and smarter. In an attempt to restore a sense of purpose, the boys come up with a solution to derail the young prodigy's research.
1 January 2008
13
S01E13
The Bat Jar Conjecture
The guys decide to compete in the university's Physics Bowl, but since Sheldon's only focus is to prove his mental superiority, the guys kick him off the team. To take his spot, they enlist his nemesis Leslie Winkle (recurring guest star SARA GILBERT).
1 January 2008
14
S01E14
The Nerdvana Annihilation
Stan goes to great lengths to compete against his rival, Chuck White, and become the new deacon of their church. Meanwhile, Roger's "temporary problem," which Stan tries to use to his advantage, causes all sorts of problems for Steve, Betsy, the rest of the family, and eventually, Stan.
1 January 2008
15
S01E15
The Shiksa Indeterminacy
Leonard, Wolowitz, and Koothrappali all become smitten with Sheldon's twin sister, Missy (guest star COURTNEY HENGGELER), and Leonard devises a plan to eliminate his rivals. The plan backfires, however, when Sheldon declares he will decide whom his sister dates.
1 January 2008
16
S01E16
The Peanut Reaction
When Penny learns that Leonard doesn't celebrate birthdays, she attempts to throw him a surprise party; she is sidetracked by Sheldon, however, who unexpectedly gets to live out one of his greatest fantasies at an electronics store.
1 January 2008
17
S01E17
The Tangerine Factor
When Penny breaks up with her boyfriend, Leonard finally gets up the courage to ask her out on a real date. When she says yes, each seeks the "wisdom" of a reluctant advisor - Sheldon.
1 January 2008