John Baragrey

Dr. Henry Spensser

Mala Powers

Anne Spensser

Otto Kruger

Dr. William Spensser

Robert Hutton

Dr. John Robert Carrington

Ross Martin

Dr. Jeremy 'Jerry' Spensser

Ed Wolff

The Colossus

Charles Herbert

Billy Spensser

Dick Nelson

Charles - Chauffeur-Butler

Roy Engel

Police Inspector

Charles Sherlock

Airline Pilot

George Douglas

Sam Harris

Larry Kerr

Harold Miller

Foster H. Phinney

Max Power

Jack Richardson

Court Shepard

Bert Stevens

Ed Wolff

Eugène Lourié

Director

Thelma Schnee

Screenplay

William Alland

Producer

Van Cleave

Original Music Composer

John F. Warren

Director of Photography

Floyd Knudtson

Editor

John B. Goodman

Art Direction

Hal Pereira

Art Direction

John P. Fulton

Visual Effects

Ralph Axness

Assistant Director

Willis Goldbeck

Writer