Michael Craig
— Dr. Richard Hare
Virginia Maskell
— Dr. Nicola Barrington
Leslie Phillips
— Dr. Tony Burke
James Robertson Justice
— Sir Lancelot Spratt
Nicholas Phipps
— Dr. Clive Cardew
Carole Lesley
— Miss Kitten Strudwick
John Le Mesurier
— Dr. Mincing
Joan Sims
— Dawn
Reginald Beckwith
— Wildewinde
Liz Fraser
— Leonora
Ambrosine Phillpotts
— Lady Spratt
Fenella Fielding
— Mrs. Tadwich
Irene Handl
— Professor MacRitchie
Esma Cannon
— Rafia Woman (uncredited)
Ronnie Stevens
— Mr. Harold Green
Nicholas Parsons
— Dr. Hinxman
Sheila Hancock
— Librarian (uncredited)
Rosalind Knight
— Doctor (uncredited)
Patrick Cargill
— Car Salesman (uncredited)
Joan Hickson
— Nurse (uncredited)
Moira Redmond
— Nurse Sally Nightingale
Michael Ward
— Dr. Flower
Angela Browne
— Susan (uncredited)
Avis Bunnage
— Mrs. Mimp (uncredited)
Cyril Chamberlain
— Shower Steward (uncredited)
Bill Fraser
— Police Sergeant (uncredited)
Warren Mitchell
— Haystack Club Manager (uncredited)
John Junkin
— Policeman (uncredited)
Marianne Stone
— Hospital Sister (uncredited)
John Moulder-Brown
— Mimps Boy (uncredited)