The Human Duplicators

George Nader

Glenn Martin

Barbara Nichols

Gale Wilson

George Macready

Prof. Vaughn Dornheimer

Dolores Faith

Lisa Dornheimer

Hugh Beaumont

Austin Welles

Richard Arlen

National Intelligence

Richard Kiel

Dr. Kolos

John Indrisano

Thor, the Butler

Ted Durant

The Galaxy Being

Tommy Leonetti

Reporter (uncredited)

Walter Maslow

Larry Barton

Lori Lyons

Benito Prezia

Margaret Teele

Blonde Lab Assistant

Alean 'Bambi' Hamilton

Brunette Lab Assistant

Walter Abel

Dr. Munson

Lon Satton

Mel Ruick

Dr. Munson (as Melville Ruick)

Kim Satana

Dr. Lin Yung