The character of Oliver Mellors was originally going to be played by Ian McShane who was a former boyfriend of lead star Sylvia Kristel. McShane pulled-out of the film when his wife objected to him partaking in sex scenes with his ex-girlfriend.
Producer André Djaoui and star Sylvia Kristel were romantically involved during filming. When Kristel cut her hair short after her last scene was shot, Djaoui didn't like her new look and ended the affair.
Sylvia Kristel mandated that written into her contract was a clause that stipulated that this movie would be made tastefully and discretely enough for it to receive the equivalent of an A-rating in the UK (= PG in the USA and Australia). The movie ended up with an R Classification in Australia and the USA and an 18 / X Classification in the UK.
Oliver Reed was offered the role of Oliver Mellors but turned it down. Reed had appeared in a lead role in Ken Russell's filmed adaptation of D.H. Lawrence's Women in Love (1969).