List of The Big Bang Theory episodes

The following is a list of episodes of the CBS sitcom The Big Bang Theory.

Like the name of the series itself, with the exception of the first episode - "Pilot" - episode titles of The Big Bang Theory always start with "The", and resemble the name of a scientific principle, theory or experiment, whimsically referencing a plot point or quirk in the episode.

As of May 31, 2012, 111 episodes have aired.

Season 1: 2007-2008
The series The Big Bang Theory began its first season on September 24, 2007 in the United States and was picked up for a full run of 17 episodes.

Season 2: 2008-2009
Season 2 of The Big Bang Theory returned to television in September 22, 2008, and contained 23 episodes.

Season 3: 2009-2010
Season 3 of The Big Bang Theory returned to television in September 21, 2009, and contained 23 episodes.

Season 4: 2010-2011
Season 4 of The Big Bang Theory returned to television in September 2010, and contained 24 episodes.

Season 5: 2011-2012
The Big Bang Theory returned to television with Season 5 in September 2011, with 24 episodes. The season finale has been announced to air on May 10, 2012.