Robert Morley was first offered the role of Lancelot Spratt but turned it down for financial reasons.
Ernest Clark (Mr.Parrish) would later play Sir Geoffrey Loftus, a Sir Lancelot Spratt type character, in the TV sitcom version of this Doctor in the House and its various TV sequels.
The medical school in the film was the old St. Georges Hospital Medical School which used to be on Hyde Park Corner (now a plush hotel). St. Georges was later moved to Tooting, in South West London.
The most popular film of its year at the UK box office.
Richard Gordon:
The author of the book "Doctor in The House" has a cameo as a Anaethetist.