Incumbent Democratic Congressman William Lacy Clay Jr. faced no difficulty in seeking another term in this liberal, St. Louis–based district over Republican Mark Byrne and Libertarian Robb Cunningham.

Freshman incumbent Congressman Russ Carnahan, a Democrat, had an easy time in winning a second term in this fairly liberal district based in the southern portion of St. Louis.

Coming from a surprisingly-close election in 2004, freshman incumbent Congressman Emanuel Cleaver, a Democrat, easily defeated Republican nominee Jacob Turk to win a third term in this fairly liberal district based in Kansas City.

Incumbent Republican Congressman Roy Blunt, the House Majority Whip, found no difficulty in winning a sixth term in his very conservative district located in southwest Missouri.

This district, based in "Little Dixie," located in northeast Missouri, has a strongly conservative bent and incumbent Republican Congressman Kenny Hulshof sought and won a sixth term against several opponents.