Ewa Aulin
Candy Christian
Charles Aznavour
Hunchback juggler
Marlon Brando
Grindl
Richard Burton
MacPhisto
James Coburn
Dr. A.B. Krankheit
John Huston
Dr. Arnold Dunlap
Walter Matthau
Gen. R.A. Smight
Ringo Starr
Emmanuel
John Astin
T.M. Christian / Jack Christian
Elsa Martinelli
Livia
Sugar Ray Robinson
Zero
Anita Pallenberg
Nurse Bullock
Lea Padovani
Silvia Fontegliulo
Florinda Bolkan
Lolita
Marilù Tolo
Marquita
Umberto Orsini
The Big Guy
Enrico Maria Salerno
Jonathan J. John
Nicoletta Machiavelli
Marquita
Neal Noorlag
Harold
Enzo Fiermonte
Al Pappone
Peter Dane
Luther
Peggy Nathan
Miss Quinby
Anthony Foutz
Mobster
Tom Keyes
Mobster
Mark Salvage
Dr. Harris
Joey Forman
The Cop
Micaela Pignatelli
Girl
Fabian Dean
The Sergeant
Christian Marquand
Film Director (uncredited)
Buck Henry
Mental Patient (uncredited)
Judith Malina
Woman (uncredited)
Julian Beck
Hippie (uncredited)
Romano Targa
Max (uncredited)
International Velvet
Extra
Crew
Buck Henry
Screenplay
Christian Marquand
Director
Mason Hoffenberg
Novel
Selig J. Seligman
Executive Producer
Robert Haggiag
Producer
Peter Zoref
Executive Producer
Terry Southern
Novel
Giuseppe Rotunno
Director of Photography
Elda Magnanti
Hairstylist
Dave Grusin
Original Music Composer
Giancarlo Cappelli
Editor
Dean Tavoularis
Art Direction
Giuliano Laurenti
Makeup Artist
Douglas Trumbull
Visual Effects
Harold E. Wellman
Visual Effects
Enrico Sabbatini
Costume Design
George R. Nelson
Set Decoration
Augie Lohman
Special Effects
Larry Shaw
Still Photographer