| Terry-Thomas | M. Barker-Rynde |
| Eric Sykes | Rumbelow |
| Dennis Price | Dr. Crossley |
| Lionel Jeffries | Inspector Hook |
| Moira Redmond | Frances |
| Katya Douglas | Rita |
| David Lodge | Richards |
| Ronnie Barker | Burton |
| Hazel Terry | Mrs. Crossley |
| Derren Nesbitt | Roger |
| Harry Locke | Riggins |
| Arthur Howard | Clerk |
| Tristram Jellinek | Asst. Clerk |
| Peter Butterworth | Barman |
| Patricia Hayes | Waitress |
| Anna Russell | Mrs. Clifford |
Technical Credits
| George Pollock | Director |
| George H. Brown | Producer |
| Jan Darnley-Smith | Asst. Director |
| Geoffrey Faithfull | Cinematographer |
| Ron Goodwin | Score Composer |
| David Pursall | Original Story,Screenwriter |
| Bert Rule | Editor |
| Jack Seddon | Original Story,Screenwriter |