Barbara Wilson as Diane Wilson

Sten Gester as Erik Engström

Robert Burton as Dr. Frederick Wilson

Bengt Blomgren as Col. Robert Bottiger

Åke Grönberg as Dr. Henrik

John Carradine as Narrator (US Re-Edit)

Gösta Prüzelius as Dr. Walter Ullman

Brita Borg as Singer (uncredited)

Doreen Denning as Anna (uncredited)

Ittla Frodi as Girlfriend in Volvo (uncredited)

Lars Åhrén as The Monster (uncredited)

Steve Conte as American Radio Supervisor #2 (US TV version) (uncredited)

Fred Hoffman as Doctor (US TV version) (uncredited)

Allan Johansson as (uncredited)

G.J. Mitchell as Diane's Psychiatrist (US TV version) (uncredited)

Chuck Niles as Second Doctor (US TV version) (uncredited)

Gustaf Unger as Air Passenger with Dark Glasses (uncredited)

Katherine Victor as Diane's Mother (US TV version) (uncredited)