The message "For Sasha" appears just before the end credits. This is a dedication to the director's daughter Sasha Cassavetes.
Director Cameo: [Nick Cassavetes] A reporter on the courthouse steps at the end.
The scene where Denise calls John from the hospital had to be re-shot because she was wearing the wrong dress.
The scene where George W. Bush is speaking about health care while John and Denise are watching TV was also shot with footage of Al Gore because the election was between the time of shooting and release.
"John Q" was originally going to be the title of Citizen Kane (1941).
The movie was shot in a group of provincial government buildings in Toronto. Adjacent to filming is a hospital. On at least one occasion, filming blocked off the access to the real emergency room of the real hospital.
This movie has the last footage of film director Ted Demme.