Liz Fraser's role was originally created for Hattie Jacques. When she had to pull out of the film due to poor health, the character was heavily rewritten for Liz. Hattie instead played a cameo part as a hospital Sister.

The cab driver's famous line to Kenneth Williams and his chimp, "I'll take you but not your brother" was writer Norman Hudis's favourite joke of the film - but was ad-libbed by the actor, also part-time cabbie and firefighter, Fred Griffiths.

Joan Sims's wine-tasting scene saw her downing an array of cold teas, water - and a real, surprise, throat-burning neat gin.