Homeboy is the first film written by Mickey Rourke. He credited as "Sir" Eddie Cook. Other films which are written by Mickey Rourke are also credited like that.
Debra Feuer, who portrays Johnny Walker's (Mickey Rourke) love interest was actually wife of Rourke at that time.
In a 1992 interview, Christopher Walken said that Mickey Rourke first told him about this project during the shooting of Heaven's Gate (1980), and that Rourke already have him in mind for the role of Wesley.