| State | Incumbent | Party | Status | Opposing Candidates |
| Alabama | Howell Heflin | Democrat | Retired: Republican victory, 52 - 46 | Jeff Sessions (Republican) Roger Bedford (Democrat) |
| Alaska | Ted Stevens | Republican | Re-elected, 77 - 13 - 10 | Jeff Whittaker (Green) Theresa Obermeyer (Democrat) |
| Arkansas | David Pryor | Democrat | Retired: Republican victory, 53 - 47 | Tim Hutchinson (Republican) Winston Bryant (Democrat) |
| Colorado | Hank Brown | Republican | Retired: Republican victory, 51 - 46 | Wayne Allard (Republican) Tom Strickland (Democrat) |
| Delaware | Joe Biden | Democrat | Re-elected, 60 - 38 | Raymond J. Clatworthy (Republican) |
| Georgia | Sam Nunn | Democrat | Retired: Democratic victory, 49 - 48 | Max Cleland (Democrat) Guy Millner (Republican) |
| Idaho | Larry E. Craig | Republican | Re-elected, 57 - 40 | Walt Minnick (Democrat) |
| Illinois | Paul Simon | Democrat | Retired: Democratic victory, 56 - 41 | Richard J. Durbin (Democrat) Al Salvi (Republican) |
| Iowa | Tom Harkin | Democrat | Re-elected, 52 - 47 | Jim Ross Lightfoot (Republican) |
| Kansas | Nancy Kassebaum | Republican | Retired: Republican victory, 62 - 34 | Pat Roberts (Republican) Sally Thompson (Democrat) |
| Kansas1 | Sheila Frahm | Republican | Defeated in Primary: Republican victory, 54 - 43 | Sam Brownback (Republican) Jill Docking (Democrat) |
| Kentucky | Mitch McConnell | Republican | Re-elected, 55 - 43 | Steve Beshear (Democrat) |
| Louisiana | Bennett Johnston Jr. | Democrat | Retired: Democratic victory, 50 - 50 | Mary Landrieu (Democrat) Woody Jenkins (Republican) |
| Maine | William Cohen | Republican | Retired: Republican victory, 49 - 44 | Susan M. Collins (Republican) Joe Brennan (Democrat) |
| Massachusetts | John Kerry | Democrat | Re-elected, 53 - 45 | William Weld (Republican) |
| Michigan | Carl Levin | Democrat | Re-elected, 58 - 40 | Ronna Romney (Republican) |
| Minnesota | Paul Wellstone | Democrat (DFL) | Re-elected, 50 - 41 - 7 | Rudy Boschwitz (Republican) Dean Barkley (Reform) |
| Mississippi | Thad Cochran | Republican | Re-elected, 71 - 27 | James Hunt (Democrat) |
| Montana | Max Baucus | Democrat | Re-elected, 50 - 45 | Dennis Rehberg (Republican) |
| Nebraska | J. James Exon | Democrat | Retired: Republican victory, 56 - 42 | Chuck Hagel (Republican) Ben Nelson (Democrat) |
| New Hampshire | Bob Smith | Republican | Re-elected, 49 - 46 | Dick Swett (Democrat) |
| New Jersey | Bill Bradley | Democrat | Retired: Democratic victory, 53 - 43 | Robert Torricelli (Democrat) Dick Zimmer (Republican) |
| New Mexico | Pete Domenici | Republican | Re-elected, 64 - 30 | Art Trujillo (Democrat) |
| North Carolina | Jesse Helms | Republican | Re-elected, 53 - 46 | Harvey Gantt (Democrat) |
| Oklahoma | Jim Inhofe | Republican | Re-elected, 57 - 40 | James Boren (Democrat) |
| Oregon | Mark Hatfield | Republican | Retired: Republican victory, 49 - 47 | Gordon H. Smith (Republican) Tom Bruggere (Democrat) |
| Rhode Island | Claiborne Pell | Democrat | Retired: Democratic victory, 63 - 35 | John F. Reed (Democrat) Nancy Mayer (Republican) |
| South Carolina | Strom Thurmond | Republican | Re-elected, 53 - 44 | Elliot Close (Democrat) |
| South Dakota | Larry Pressler | Republican | Defeated, 51 - 49 | Tim Johnson (Democrat) |
| Tennessee | Fred Thompson | Republican | Re-elected, 61 - 37 | Houston Gordon (Democrat) |
| Texas | Phil Gramm | Republican | Re-elected, 55 - 44 | Victor Morales (Democrat) |
| Virginia | John Warner | Republican | Re-elected, 53 - 47 | Mark Warner (Democrat) |
| West Virginia | Jay Rockefeller | Democrat | Re-elected, 77 - 23 | Betty Burkes (Republican) |
| Wyoming | Alan Simpson | Republican | Retired: Republican victory, 54 - 42 | Michael B. Enzi (Republican) Joyce Jansa Corcoran (Democrat) |