Research chemist Barnaby Fulton works on a fountain of youth pill for a chemical company. One of the labs chimps gets loose in the laboratory and mixes chemicals, but then pours the mix into the water cooler. When trying one of his own samples, washed down with water from the cooler, Fulton begins to act just like a twenty-year-old and believes his potion is working. Soon his wife and boss are also behaving like children.
| Writing | Charles Lederer | Screenplay |
| Writing | Ben Hecht | Screenplay |
| Production | Sol C. Siegel | Producer |
| Directing | Howard Hawks | Director |
| Editing | William B. Murphy | Editor |
| Camera | Milton Krasner | Director of Photography |
| Art | Walter M. Scott | Set Decoration |
| Writing | Harry Segall | Story |
| Art | Lyle R. Wheeler | Art Direction |
| Writing | I. A. L. Diamond | Screenplay |
| Art | George Patrick | Art Direction |
| Art | Thomas Little | Set Decoration |
| Sound | Roger Heman Sr. | Sound |
| Sound | Leigh Harline | Music |
| Costume & Make-Up | Charles LeMaire | Other |
| Crew | Ray Kellogg | Special Effects |
| Sound | Earle Hagen | Orchestrator |
| Sound | W. D. Flick | Sound |
| Costume & Make-Up | Ben Nye | Makeup Artist |
| Sound | Lionel Newman | Music Director |
| Costume & Make-Up | Travilla | Costume Designer |
| Writing | Howard Hawks | Screenplay |
| Costume & Make-Up | Esperanza Corona | Hairstylist |
| Costume & Make-Up | Louise Miehle | Hairstylist |
| Costume & Make-Up | Bill Riddle | Makeup Artist |
| Costume & Make-Up | Allan Snyder | Makeup Artist |
| Costume & Make-Up | Helen Turpin | Hairstylist |
| Directing | Paul Helmick | Assistant Director |
| Directing | Don Torpin | Assistant Director |
