This is a list of the current House seats and the incumbents occupying them. All 435 of these seats are up for election on 2 November 2004.

There have been 1 death, 6 resignations, and 2 changes of party affiliation in the 108^th House.

• Hawaii CD 2: Democratic Congressman Patsy Takemoto Mink, a member of the 107th Congress, passed away on 28 September 2002. She was re-elected posthumously on 5 November 2002. Hawaii will hold a 4 Janaury 2003 Special Election to fill her seat.
• Texas CD 19: On 12 November 2003, Republican Congressman Larry Combest announced that he will submit his resignation from Congress effective 31 May 2003.
• South Dakota At-Large: On 8 December 2003, Congressman William Janklow (Republican) was convicted of second-degree manslaughter in the death of a motorcyclist during a traffic accident. The Congressman resigned on 20 January 2004.
• Kentucky CD 6: Congressman Ernie Fletcher (Republican), who served in the U.S. House from 1999 through 2003, was elected Governor of Kentucky on 4 November 2003 and after resigning from the U.S. House, became Governor of Kentucky on 9 December 2003. Congressman A.B. "Ben" Chandler (Democrat) was elected to fill this vacant seat in a special election on 17 February 2004.
• Texas CD 4: On 20 January 2004, the House received a communication from the Chairman of the Democratic Caucus notifying the House of the resignation of Congressman Ralph Hall from the Democratic Caucus, effective 5 January 2004. Congressman Hall is now affiliated with the Republican Party.
• South Dakota At-Large: On 1 June 2004, the voters of South Dakota elected Democrat Stephanie Herseth to fill the seat vacated by former Republican Congressman William Janklow. Congressman Herseth took the oath of office on 3 June 2004.
• North Carolina CD 1: Congressman Frank W. Ballance, Jr., submitted his resignation from the House on 8 June 2004 for health reasons. His resignation becomes effective at 11:59 p.m. on 11 June 2004.
• North Carolina CD 1: In a 20 July 2004 Special Election, the voters of North Carolina elected Democrat G. K. Butterfield to fill the seat vacated by former Democratic Congressman Frank W. Ballance, Jr. Congressman Butterfield took the oath of office on 21 July 2004.
• Louisiana CD 5: Congressman Rodney Alexander, who was first elected in 2002 as a Democrat, switched to Republican Party in August 2004.
• Nebraska CD 1: Republican Congressman Doug Bereuter resigned from the House of Representatives effective at the close of business on 31 August 2004. On 16 December 2003 the congressman announced that he would not seek re-election in 2004.
• Florida CD 14: Republican Congressman Porter J. Goss resigned from the House of Representatives effective close of business 23 September 2004. On 10 August 2004 Congressman Goss was nominated for Director of the Central Intelligence Agency by President George W. Bush. He was confirmed by the Senate on 22 September and sworn on 24 September 2004.