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.
You can now watch Monkey Business online on the following streaming providers in the United States.
| Directing | Howard Hawks | Director |
| Editing | William B. Murphy | Editor |
| Writing | Ben Hecht | Screenplay |
| Writing | Charles Lederer | Screenplay |
| Production | Sol C. Siegel | Producer |
| Camera | Milton Krasner | Director of Photography |
| Art | Walter M. Scott | Set Decoration |
| Writing | Harry Segall | Story |
| Writing | I. A. L. Diamond | Screenplay |
| Art | George Patrick | Art Direction |
| Art | Lyle R. Wheeler | Art Direction |
| Art | Thomas Little | Set Decoration |
| Costume & Make-Up | Ben Nye | Makeup Artist |
| Sound | Lionel Newman | Music Director |
| Costume & Make-Up | Travilla | Costume Designer |
| Crew | Ray Kellogg | Special Effects |
| Costume & Make-Up | Charles LeMaire | Other |
| Sound | Leigh Harline | Music |
| Sound | Earle Hagen | Orchestrator |
| Sound | Roger Heman Sr. | Sound |
| Sound | W. D. Flick | Sound |
| 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 |
