 | Richard Benjamin als Tom |
 | Dyan Cannon als Christine |
 | James Coburn als Clinton |
 | Joan Hackett als Lee |
 | James Mason als Philip |
 | Ian McShane als Anthony |
 | Raquel Welch als Alice |
 | Yvonne Romain als Sheila |
 | Pierre Rosso als Vittorio |
| Serge Citon als Guido |
| Roberto Rossi als Captain |
| Elaine Geisinger als American Woman |
| Elliot Geisinger als American Man |
| Jack Pugeat als Silver Salesman |
| Maurice Crosnier als Concierge (uncredited) |
| Martial als Locksmith (uncredited) |
| Edward Warschilka | Editor |
| Anthony Perkins | Writer |
| Herbert Ross | Director |
| Stephen Sondheim | Writer |
| Herbert Ross | Producer |
| Gerry Turpin | Director of Photography |
| Bob Penn | Still Photographer |
| Stanley O'Toole | Executive Producer |
| John Jarvis | Set Decoration |
| Derek V. Browne | Camera Operator |
| Tony Roman | Art Direction |
| Joel Schumacher | Costume Design |
| Ken Adam | Production Design |
| Billy Goldenberg | Original Music Composer |
| Annabel Davis-Goff | Script Supervisor |
| Mary Bredin | Hairstylist |
| Harry Frampton | Makeup Artist |
| Peter Frampton | Makeup Artist |
| Alaine Scemama | Hairstylist |
| Mishka Cheyko | Assistant Director |
| William C. Gerrity | Assistant Director |
| David Dockendorf | Sound Mixer |
| Derek Holding | Sound Editor |
| Richard Oswald | Sound Editor |
| Cyril Swern | Sound Recordist |
| Dan Wallin | Sound Re-Recording Mixer |
| Fred Stromsoe | Stunts |
| Don Zimmerman | Assistant Editor |
