Paul Hubschmid

John McLaren

Madeleine Fischer

Katy Dandridge

Fiorella Mari

Mary McLaren

Ivo Garrani

Professor Herbert Weisse

Dario Michaelis

Peter Leduq

Sam Galter

Randowsky

Jean-Jacques Delbo

Sergei Boetnikov

Peter Meersman

General van Dorff (uncredited)

Massimo Zeppieri

Dennis McLaren (uncredited)

Annie Bernal

Lab Assistant (uncredited)

Giacomo Rossi Stuart

Stuart (uncredited)

Gérard Landry

Landowsky (uncredited)

Shane Rimmer

John McLaren (uncredited) (voice)

Paolo Heusch

Mario Bava