William Holden

Richard Thorn

Lee Grant

Ann Thorn

Jonathan Scott-Taylor

Damien Thorn

Robert Foxworth

Paul Buher

Nicholas Pryor

Charles Warren

Lew Ayres

Bill Atherton

Sylvia Sidney

Aunt Marion

Lance Henriksen

Sergeant Neff

Elizabeth Shepherd

Joan Hart

Ian Hendry

Michael Morgan (uncredited)

Leo McKern

Carl Bugenhagen (uncredited)

Allan Arbus

Pasarian

Meshach Taylor

Dr Kane

Paul Cook

Colonel

Felix Shuman

Dr. Fiedler

James Spinks

Technician #1