Marilyn Hanold

Princess Marcuzan

James Karen

Dr. Steele

Lou Cutell

Dr. Nadir

Nancy Marshall

Karen Grant

David Kerman

General Bowens

Robert Reilly

Col. Frank Saunders / Frankenstein

Robert Alan Browne

Martian Crewmember (uncredited)

Robert Fields

Reporter (uncredited)

Bruce Glover

Martian Crewmember / The Monster (uncredited)

Robert Gaffney