Tony Randall

Hercule Poirot

Anita Ekberg

Amanda Beatrice Cross

Robert Morley

Captain Hastings

Maurice Denham

Inspector Japp

Guy Rolfe

Dr. Duncan Doncaster

Sheila Allen

Lady Diane

James Villiers

Franklin

Julian Glover

Don Fortune

Grazina Frame

Betty Barnad

Clive Morton

Mister X

Cyril Luckham

Sir Carmichael Clarke

Richard Wattis

Wolf

David Lodge

Sergeant

Patrick Newell

Cracknell

Austin Trevor

Judson

Alison Seebohm

Miss Sparks

Windsor Davies

Dragbot

Sheila Reid

Mrs. Fortune

Drewe Henley

Bowling Alley Attendant (uncredited)

Sally Douglas

Glamorous Girl in Gaming Club (uncredited)