The hilarity begins when professor Sherman Klump finds romance with fellow DNA specialist, Denise Gaines, and discovers a brilliant formula that reverses aging. But Sherman's thin and obnoxious alter ego, Buddy Love, wants out...and a big piece of the action. And when Buddy gets loose, things get seriously nutty.
| Production | James D. Brubaker | Executive Producer |
| Production | Eddie Murphy | Executive Producer |
| Camera | Dean Semler | Director of Photography |
| Editing | William Kerr | Editor |
| Production | Karen Kehela Sherwood | Executive Producer |
| Production | Jerry Lewis | Executive Producer |
| Writing | Paul Weitz | Screenplay |
| Directing | Peter Segal | Director |
| Writing | Barry W. Blaustein | Screenplay |
| Writing | David Sheffield | Screenplay |
| Writing | Chris Weitz | Screenplay |
| Production | Brian Grazer | Producer |
| Production | Tom Shadyac | Executive Producer |
| Sound | David Newman | Music |
| Costume & Make-Up | Rick Baker | Special Effects Makeup Artist |
| Directing | Susan Bierbaum | Script Supervisor |
| Sound | José Antonio García | Sound Mixer |
| Costume & Make-Up | Sharen Davis | Costume Design |
| Visual Effects | Jon Farhat | Visual Effects Supervisor |
| Production | Arlene Kehela | Associate Producer |
| Sound | Jonathan Fuh | Boom Operator |
| Art | Greg Papalia | Art Direction |
| Camera | Bruce McBroom | Still Photographer |
| Crew | Alan Oliney | Stunt Coordinator |
| Art | John H. Anderson | Set Decoration |
| Camera | Joseph D. Urbanczyk | Camera Operator |
| Crew | Greg Salmon | Cableman |
| Production | Jim Whitaker | Co-Producer |
| Costume & Make-Up | Nena Smarz | Makeup Department Head |
| Crew | Bronwyn Preston | Unit Publicist |
| Crew | Mickey Gilbert | Stunt Coordinator |
| Sound | Happy Walters | Music Supervisor |
| Art | William A. Elliott | Production Design |
| Sound | Gary Jones | Music Supervisor |
| Production | Michael Ewing | Co-Producer |
| Writing | Jerry Lewis | Characters |
| Writing | David Sheffield | Story |
| Writing | Barry W. Blaustein | Story |
| Writing | Steve Oedekerk | Story |
| Sound | Dave Jordan | Music Coordinator |
