While filming in Harlem, Larry Cohen was accosted by local gangsters who threatened to disrupt the shoot unless they were paid off. Instead, Cohen offered them small roles in the film. They helped so enthusiastically that they attended the premiere to sign autographs.
Originally offered to Sammy Davis Jr., who turned it down because he could not pay the $10,000 for the script due to his issues with the Internal Revenue Service at the time. Davis wanted a project where he would be the star and not play second banana to Frank Sinatra and Dean Martin. When Larry Cohen's deal with Davis fell through, Samuel Z. Arkoff and American-International Pictures took up the project.
Gloria Hendry said in an interview that she was cast because she was willing to do the nudity the role required. Nudity was no problem for her because she had posed for "Playboy" when she was a model before becoming an actress. However, she said it was an issue for some other black actresses; as a general rule, they didn't do nudity because it was deemed as a reminder of the past when black slaves would be forced to strip down so that their masters could get a good look at the kind of stock they were attempting to purchase. That "no-nudity" attitude soon changed, though, as Blaxploitation and other films at that time required nudity, so more and more actresses were willing to strip off their clothes if they wanted to work.
The sequence in the barber shop where doomed gangster Mr. Grossfeld is getting his daily shave proved to be challenging to shoot. Director Larry Cohen instructed the real-life barber to accidentally nick the actor's face while shaving him, but no matter how many times he tried, the actor would not bleed.