The role of Arnold Crouch was originally intended for Dudley Moore but he was signed to a film in the U.S. It was then offered to Terry Scott who developed an aneurysm and had to withdraw. Director Ray Cooney then assumed the role himself, having been the original actor in the out-of-town preview, before it opened in the West End.
It was the last film to feature appearances by Cicely Courtneidge and Jack Hulbert who had been a leading celebrity couple in the 1930s and 1940s.
'Not Now Darling' opened at the Brooks Atkinson Theater on October 29, 1970 and ran for 21 performances.
Jackie Pallo and Geraldine Gardner (as Trudie Van Doorn/Trudie van Doorn) receive an "Introducing" credit.