John Belushi was offered a role in this film numerous times, but he originally turned it down. He eventually accepted the role, but died shortly afterwards. The producers were excited of having him on the poster wearing a diaper, even though no such scene appeared in the script. This was in the period Penny Marshall was supposed to direct based on a screenplay by John Hughes.
The film's director, Martha Coolidge, said of this movie in an interview with 'Rediscover the 80s' - ''Paramount insisted on topless girls running down the hall because they thought the formula demanded it and it was totally gratuitous. I hated putting them in for no reason and argued against it. But when the film was previewed the audience, particularly young women and girls, hated the nudity so Paramount then asked me to cut as much of it out as I could!. They had thought they were going to get a Porky's - A Casa do Amor e do Riso (1981) but the script was more from a girl's point of view (as was Sonhos Rebeldes (1983)). It was actually a romance and certainly the women writers and I weren't the people to get a Porky's - A Casa do Amor e do Riso (1981) from. The movie wasn't what the execs thought it would be, they freaked, took me off the movie, cut it down and tried to make the humor broader which made it more disjointed. The entire budget was minuscule and the music was given only [US] $20,000! For comparison, the Sonhos Rebeldes (1983) soundtrack (not including score) cost [US] $150,000. The whole 'Joy of Sex' experience was pretty miserable. We were under constant pressure and scrutiny to do the impossible, we had eight days of prep, twenty days to shoot and my A.D. [assistant director] quit because he was so angry. I learned that I can't always save the day or be a hero and you have to protect yourself at all times. I did find some very talented actors though!''.
In the mid 1970s, Paramount Pictures paid a great amount of money to secure the rights to Alex Comfort's sex manual 'The Joy of Sex' (1972), just so they could use the title, which they found to be highly commercial. In 1978, they hired Charles Grodin to write a script, telling him the movie "could be about anything". Grodin decided to use this exact situation as the premise: a Hollywood writer struggles to write a script based on a sex manual after a big studio acquires the rights. When he finished his first draft, Paramount passed. Grodin finally managed to get his screenplay green lit by MGM as Promessa é Dívida (1985). Note that in that movie, the sex manual is called "Joy In Sex".
John Hughes wrote an early version of the script which consisted of several unrelated vignettes. Penny Marshall was offered to direct this version in early 1982.
Martha Coolidge had a dispute with the studio in the editing room. She shot several scenes with gratuitous nudity, but chose to keep them out of the film during the cutting process. The studio disagreed and eventually fired her. Coolidge decided not to request an Alan Smithee credit, though she has said in interviews that she sometimes regrets that decision.