Paul Stevens
Doctor Allan Barnes
Claudette Nevins
Pam Albright
Anne Collings
Miss Goodrich
Bill Walker
Lieutenant Martin
Martin Lavut
Michael Radin
Leo Leyden
Doctor Soames
Norman Ettlinger
Professor Quincey
W.B. Brydon
Anderson (as Bill Bryden)
Jim Moran
Jim Moran
Eleanor Beecroft
Mrs. Kelly
Ray Lawlor
Lab Technician
Rudi Linschoten
Mime in Nightmare
Stephen Ker Appleby
Museum Guide (as Steven Appleby)
Harry Blackstone
Self (in introduction added to video version) (uncredited)
Nancy Island
Girl Who Is Killed (uncredited)
Paul Nevens
Demon of the Mask (uncredited)