When this movie was originally released in 1969, some newspapers refused to advertise it, compelling cinephiles to call up their local theaters to learn the title. A few theaters even temporarily expanded their marquees to fit the entire title. Other theaters truncated the title to "Heironymous Merkin".
Joan Collins said that this movie contributed to the decline of her marriage to Writer, Producer, and Director Anthony Newley.
Joan Collins wrote in her biography Past Imperfect that when she saw the film in a private screening in London she knew there was no hope of living as husband and wife again with Anthony Newley.
Playboy Magazine devoted ten pages of one of its 1969 issues to this movie, complete with photographs of many of the nude female stars. Connie Kreski was cast as Mercy Hummpe after being named Playmate of the Year in 1969.
According to all references on the soundtrack LP, as well as the movie posters, the correct spelling of the title is "Can Heironymus Merkin Ever Forget Mercy Humppe and Find True Happiness" - that is, with the E before the I, contrary to the standard spelling of Hieronymus.