Dr. Victor Stein

Peter Cushing

Dr. Hans Kleve

Francis Matthews

Margaret Conrad

Eunice Gayson

Karl

Michael Gwynn

Fritz

Lionel Jeffries

Dr. Bergman

John Welsh

Dwarf

Oscar Quitak

Up Patient

Richard Wordsworth

President

Charles Lloyd Pack

Inspector

John Stuart

Kurt

Michael Ripper

Countess Barscynska

Margery Cresley

Molke

Arnold Diamond

Countess Barscynska

Marjorie Gresley

Vera Barscynska

Anna Walmsley

Janitor

George Woodbridge

Boy

Ian Whittaker

Girl

Avril Leslie

Manservant (uncredited)

John Tatham

Kleine (uncredited)

Eugene Leahy

Policeman (uncredited)

Charles Gilliard

Patient (uncredited)

Jimmy Charters

Inga (uncredited)

Julia Nelson

Joseph the Groom (uncredited)

Robert Brooks Turner