Trey Parker, Matt Stone, and fans in general often joked that a majority of the people who saw this movie were under 17, but got into the R rated movie by buying tickets to the PG-13 rated Will Smith flop: Wild Wild West (1999). The urban legend became so popular in 1999 that it would be spoofed in an episode of South Park (1997).
In the Guinness World Records 2001, this film was said to have the most profanity used in an animated film. The book cited a total of 399 swear words, including 146 uses of the word "fuck," along with 199 offensive gestures and 221 acts of violence.
When the children are in rehab a poster in the back of Mr. Mackey's room reads, "Get High!!! On Pottery," which was a quote from a high school teacher of Matt Stone's. The original quote was, "Son, you need to know not to use pot as a natural high. Instead of getting high with pot, get high with pottery."
Paramount Pictures originally asked Trey Parker and Matt Stone if they could make a PG-13 rated film. They said no and would not agree to make a movie until the studio agreed that the final product would be rated R.
Trey Parker stated that he is a fan of the musical Les Misérables. The song "La Resistance" is based on the Les Misérables song "One Day More."