James Franciscus
Role: Carlo Giordani
Karl Malden
Role: Franco Arnò
Catherine Spaak
Role: Anna Terzi
Pier Paolo Capponi
Role: Police Supt. Spini
Horst Frank
Role: Dr. Braun
Rada Rassimov
Role: Bianca Merusi
Aldo Reggiani
Role: Dr. Casoni
Carlo Alighiero
Role: Dr. Calabresi
Vittorio Congia
Role: Righetto (cameraman)
Ugo Fangareggi
Role: Gigi the Loser
Tom Felleghy
Role: Dr. Esson
Emilio Marchesini
Role: Dr. Mombelli
Fulvio Mingozzi
Role: Spimi's man
Corrado Olmi
Role: Morsella
Umberto Raho
Role: Manuel's ex-lover
Jacques Stany
Role: Prof. Manera
Stefano Oppedisano
Role: Taxi driver
Ada Pometti
Role: Telephone operator
Marie Louise Sinclair
Role: Film starlet
Cinzia De Carolis
Role: Lori
Werner Pochath
Role: Manuel
Tino Carraro
Role: Prof. Fulvio Terzi
Ettore Arena
Role: Billiard Player (uncredited)
Aristide Caporale
Role: Smoker in the Billiard Hall (uncredited)
Giovanni Di Benedetto
Role: Chief of Police Salmi (uncredited)
Margherita Horowitz
Role: Lori's Babysitter (uncredited)
Giuseppe Marrocco
Role: Man at Table in the Saint Peter's Club (uncredited)
Gennarino Pappagalli
Role: Man in the Terzi's Institute (uncredited)
Aldo Parenti
Role: (uncredited)
Franco Ukmar
Role: Policeman - Speaks with Morsella About Food (uncredited)