The number of seats up for election went back to 435, in accordance with reapportionment and redistricting resulting from the 1960 census.

5th district incumbent Dale Alford chose to run for governor rather than face Wilbur Mills in a primary, and 6th district incumbent Catherine Dorris Norrell retired after serving out the remainder of her husband's term.

[2] Eight new seats were gained in reapportionment, including 4 additional districts in Greater Los Angeles alone as well as others in San Diego, the Northern Central Valley, Alameda County, and the Central Coast, increasing the delegation from 30 to 38 seats.

Florida gained 4 new districts at reapportionment: the 3rd around Miami, the 9th in the Panhandle, the 10th around Tampa, and the 11th in Orlando and the nearby Atlantic coast.

[2] Kansas lost one seat at reapportionment and redistricted from 6 to 5, combining the existing southwestern 5th and northwestern 6th districts into a single district, in which incumbents J. Floyd Breeding and Bob Dole ran against each other, and making modest boundary changes elsewhere.

[2] Maryland gained an eighth seat at reapportionment and chose to elect it at-large.

Minnesota lost one seat at reapportionment, and the 7th saw the largest change, with its territory split between the existing 2nd and 6th districts.

[2] Mississippi lost one seat at reapportionment, and merged the 2nd and 3rd districts without making other boundary changes.