A popular misconception holds that River Phoenix was set to play the lead before his tragic death. This is not entirely accurate. River was a big fan of the book, and as the film version entered various stages of readiness, he was always the front-runner. However, prior to his death, he had declined the role due to a combination of feeling he was too old to play a fifteen year old and trying to broaden his range with more adult roles.
The movie became one of several subjects to a lawsuit filed shortly after the 1997 shooting at Heath High School, where a group of praying students was shot and killed by a fourteen-year-old. The infamous (now disbarred) attorney Jack Thompson, who filed the suit, claimed that this film, as well as several video game companies, two internet porn sites, and Natural Born Killers (1994) were directly responsible for influencing the shooter. The case was ultimately dismissed in 2001.
A drug consultant was hired for authenticity and was present on set. Leonardo DiCaprio outlined how to talk like an addict to the Los Angeles Times. "The voice: you go down an octave," DiCaprio explained. "Even when you raise your voice it's like you got this frog in your throat. It's not necessarily being tired and it's not necessarily like being drunk. It's sort of like your body becomes jelly and all your bones and everything become completely relaxed. You just feel at peace. Supposedly. I don't know. I've never done it. Right?"
Jim Carroll was unaware of who Leonardo DiCaprio was at first. "When they first told me it was gonna be Leo, I didn't know who he was," Carroll told The Los Angeles Times. "If they'd said the kid from Growing Pains (1985), I would have known, because when I first saw that kid, I said, 'This kid has a lot of presence.' I said, 'That kid is very pretty. He's gonna do well.'"
The songs "Catholic Boy" and "People Who Died", which play in the film, were written and sung by Jim Carroll. They were also performed by The Jim Carroll Band.