Boris Karloff as Prof. Marcus Monserrat

Catherine Lacey as Estelle Monserrat

Elizabeth Ercy as Nicole

Ian Ogilvy as Mike Roscoe

Victor Henry as Alan

Sally Adams as Laura Ladd

Meier Tzelniker as The Jewish Baker

Gerald Campion as Customer in China Shop

Susan George as Audrey Woods

Ivor Dean as Insp. Matalon

Peter Fraser as Detective George

Martin Terry as Tobacconist

Bill Barnsley as Constable in Fur Store

Maureen Booth as Dancer

Toni Daly as Vocalist

Arnold L. Miller as Taxi driver

Alf Joint as Ron, the mechanic