The neighborhood where the film takes place is the same street where the film's director, F. Gary Gray, grew up in South Central, Los Angeles. Principal houses that were used for filming were houses of old friends of the director. The scene where Deebo punches Red into the air is the house that Gray grew up in.
In the flashback scene where Smokey is in the car with Hector and his friend, two men can be seen sitting on a block wall in the background. The men were residents of the neighborhood who wanted to be difficult towards the production staff, knowing they couldn't tell them what to do on their property. They remained in the shot despite offers from the staff which included compensation or a walk-on role in the film.
The trivia items below may give away important plot points.
The outfit that Ice Cube wears throughout the movie is also the same outfit worn by Ice Cube's son in the movie Straight Outta Compton. it's in the scene when the news reports Eazy-E having aids. O'shea Jackson Jr. plays as his father in the movie. The movie also shows O'shea Jackson Jr. (as Ice Cube) writing the script to Friday.
Ice Cube (Craig) Bernie Mac (The Reverend), AJ Johnson (Ezel) ,Tiny Lister (Deebo) , Faizon Love (Big Worm) and Ronn Riser (Stanley) all appear together 3 years later on Players Club which was also written and directed by Ice Cube.