Director Bryan Forbes looked for the house with the turret as a film location. When he went to the owner for permission, she asked who was in the movie. When told that an American actress named Kim Stanley, the woman blanched, stepped back, and said that Stanley was one of her oldest friends whom she had not seen in seventeen years.
In an early draft of the screenplay, Billy and Myra were both male, with Director Bryan Forbes planning to cast Sir Alec Guinness and Sir Tom Courtenay as the homosexual couple. Courtenay agreed to play the role but Guinness, however, turned it down. Forbes decided then to completely re-write the screenplay.
During filming, Sir Richard Attenborough developed kidney stones and was unable to work for a day. Since filming was on such a tight schedule, Director Bryan Forbes got into costume and played his role for some shots.
In one of the scenes, Sir Richard Attenborough passes a street ad promoting stage musical "Oh, What a Lovely War!". Five years later, he directed a movie adaptation of the musical.