Edward Connell

David Fielding (as Skip Shimer)

Barbara Hewitt

Susan Turner

Jack Woods

Asmodeus

Frank Bonner

Jim Hudson (as Frank Boers Jr.)

Robin Christopher

Vicki (as Robin Snider)

James Phillips

Reporter Sloan (as Jim Phillips)

Fritz Leiber Jr.

Dr. Arthur Watermann (as Fritz Leiber)

Patrick Burke

Doctor Branson

Sharon Gray

Nurse

Louis Clayton

Old man in cave

Norvelle Brooks

Irving L. Lichtenstein

James Dwion

The Orderly

Forrest J. Ackerman

Doctor on Tape Recorder (voice) (uncredited)

Jack H. Harris

Detective Harrison (uncredited)

Jack Woods

Dennis Muren