ER 1994 - 2009 : List of All Seasons

The fifteenth season of the American fictional drama television series ER premiered on September 25, 2008 and concluded on April 2, 2009, in a two-hour episode preceded by a one-hour retrospective special. The final season consists of 22 episodes.

The fourteenth season of the American fictional drama television series ER first aired on September 27, 2007 and concluded on May 15, 2008. The fourteenth season consists of 19 episodes. 22 were initially ordered by NBC, but the season was shortened due to the 2007–2008 Writers Guild of America strike.

The thirteenth season of the American fictional drama television series ER first aired on September 21, 2006 and concluded on May 17, 2007. The thirteenth season consists of 23 episodes.

The twelfth season of the American fictional drama television series ER first aired on September 22, 2005 and concluded on May 18, 2006. The twelfth season consists of 22 episodes.

The eleventh season of the American fictional drama television series ER first aired on September 23, 2004 and concluded on May 19, 2005. The eleventh season consists of 22 episodes.

The tenth season of the American fictional drama television series ER first aired on September 25, 2003 and concluded on May 13, 2004. The tenth season consists of 22 episodes.

The ninth season of the American fictional drama television series ER first aired on September 26, 2002 and concluded on May 15, 2003. The ninth season consists of 22 episodes.

The eighth season of the American fictional drama television series ER first aired on September 27, 2001 and concluded on May 16, 2002. The eighth season consists of 22 episodes.

The seventh season of the American fictional drama television series ER first aired on October 12, 2000 and concluded on May 17, 2001. The seventh season consists of 22 episodes.

The sixth season of the American fictional drama television series ER first aired on September 30, 1999 and concluded on May 18, 2000. The sixth season consists of 22 episodes.

The fifth season of the American fictional drama television series ER first aired on September 24, 1998 and concluded on May 20, 1999. The fifth season consists of 22 episodes.

The fourth season of the American fictional drama television series ER first aired on September 25, 1997 and concluded on May 14, 1998. The fourth season consists of 22 episodes.

The third season of the American fictional drama television series ER first aired on September 26, 1996 and concluded on May 15, 1997. The third season consists of 22 episodes.

The second season of the American fictional drama television series ER first aired on September 21, 1995 and concluded on May 16, 1996. The second season consists of 22 episodes.

The first season of the American fictional drama television series ER aired from 1994–1995 with 25 episodes. The 2-hour pilot episode aired on September 19, 1994 and was followed by 24 other episodes, including the season finale that aired on May 18, 1995.