According to Michael Winner's biography, Charles Bronson's alcoholic brother often visited the set to borrow money. Bronson was careful not to give him too much in case someone might kill him for it. He was later found dead in a cheap hotel room having been stabbed in the buttocks.
Producers Menahem Golan and Yoram Globus wanted Isaac Hayes to compose the music. Director Michael Winner refused and brought in Led Zeppelin guitarist, Jimmy Page, who at the time was his next-door neighbor.
The odd numbered Death Wish movies take place in New York City, where the even numbered ones take place in Los Angeles.
In an interview, Silvana Gallardo (who played the housekeeper) said the rape scene was "grueling" and took about six days to film. To prepare for the role, she talked to an actual rape victim. She also said the scene was mostly improvised and that the actors who played the criminals raping her would immediately cover her up with a robe or blanket when Michael Winner yelled "CUT!"
The film was shot on location and depicted actual "sleazy" areas of the city. Twenty off-duty men of the Los Angeles Police Department were hired to protect the film cast and crew from potential trouble.