David Hemmings as Marcus Daly

Daria Nicolodi as Gianna Brezzi

Gabriele Lavia as Carlo

Macha Méril as Helga Ulmann

Eros Pagni as Supt. Calcabrini

Giuliana Calandra as Amanda Righetti

Piero Mazzinghi as Bardi

Glauco Mauri as Prof. Giordani

Clara Calamai as Marta

Aldo Bonamano as Carlo's Father

Liana Del Balzo as Elvira

Vittorio Fanfoni as Cop Taking Notes

Dante Fioretti as Police Photographer

Geraldine Hooper as Massimo Ricci

Jacopo Mariani as Young Carlo

Furio Meniconi as Rodi

Fulvio Mingozzi as Agent Mingozzi

Lorenzo Piani as Fingerprint Cop

Salvatore Puntillo as Police Agent

Piero Vida as Fat Cop

Nicoletta Elmi as Olga

Dario Argento as Murderer's Hands (uncredited)

Salvatore Baccaro as Fruit Vendor (uncredited)

Omero Capanna as Hitman (uncredited)

Bruno Di Luia as Concerned Man in Restroom (uncredited)

Attilio Dottesio as Florist (uncredited)

Tom Felleghy as Surgeon (uncredited)

Glauco Onorato as (uncredited)

Marilù Tolo as Carol (archive footage) (uncredited)

Franco Vaccaro as Pietro Valgoi (uncredited)

Gianni Di Segni as Rabbi (uncredited)

Mario Pascucci as Library Caretaker (uncredited)