Leigh McCloskey as Mark Elliot

Irene Miracle as Rose Elliot

Eleonora Giorgi as Sara

Daria Nicolodi as Elise Stallone Van Adler

Sacha Pitoëff as Kazanian

Alida Valli as Carol

Veronica Lazăr as Nurse

Gabriele Lavia as Carlo

Feodor Chaliapin Jr. as Professor Arnold / Dr. Varelli

Leopoldo Mastelloni as John, the Butler

Ania Pieroni as Musical Student

James Fleetwood as Cook

Rosario Rigutini as Man

Ryan Hilliard as Shadow

Paolo Paoloni as Music Teacher

Fulvio Mingozzi as Cabdriver

Luigi Lodoli as Bookbinder

Rodolfo Lodi as Old Man

Dario Argento as Narrator (voice) (uncredited)

Ettore Martini as Burning Building Cop (uncredited)

Corinne Dunne as Tenant in New York Building (uncredited)

Filippo Perego as Tenant in New York Building (uncredited)