Darren McGavin
— Carl Kolchak
Jo Ann Pflug
— Louise Harper
Simon Oakland
— Tony Vincenzo
Scott Brady
— Capt. Schubert
Wally Cox
— Mr. Berry
Margaret Hamilton
— Prof. Crabwell
Richard Anderson
— Dr. Richard Malcolm
John Carradine
— Llewellyn Crossbinder
Al Lewis
— Tramp
Nina Wayne
— Charisma Beauty
Virginia Peters
— Wilma Krankheimer
Kate Murtagh
— Janie Watkins
Ivor Francis
— Dr. Webb
Diane Shalet
— Joyce Gabriel
Anne Randall
— Policewoman Sheila
Francoise Birnheim
— Restaurant Woman
Regina Parton
— Merissa (Ethel Parker)
David Armstrong
— Police Officer (uncredited)
Margaret Bacon
— Reporter (uncredited)
Al Beaudine
— Reporter (uncredited)
Loren Brown
— Bar Patron (uncredited)
Bill Clark
— Bar Patron (uncredited)
Robert Cole
— Reporter (uncredited)
Tony Dante
— Reporter (uncredited)
George DiCenzo
— Underground Tour Guide (uncredited)
Rudy Doucette
— Man on Tour (uncredited)
Bob Harks
— Bar Patron (uncredited)
Chester Hayes
— Bar Patron (uncredited)
Bill McLean
— Charlie the Bartender (uncredited)
Joe Phillips
— Detective (uncredited)