Eric Bana spent two days living with Mark Brandon Read so he could get a better understanding of how to play his character in the film.
Eric Bana admitted to eating junk food for four weeks to put on the extra weight needed to play the 1986 Chopper.
Robert Rabiah arrived at the "Chopper" audition early and was rehearsing with an acting friend outside; 30 minutes later he was swooped on by a 15-man SWAT team. Apparently in the scene he was testing for he gets shot, so true to the "Method," he went through the action. A lady driving by saw what she thought was a real shooting and called it in. It took director Andrew Dominik and casting agent Gregory Apps to explain what was going on. A week later Rabiah got the call and got the part. He was quoted as saying to the director, "How much reality do you want?"
Until The Wolf of Wall Street (2013), "Chopper" was the highest-grossing R18+ film in Australian history.
Well-known Australian singer/songwriter Billy Thorpe was strongly opposed to the use of his version of "Somewhere Over The Rainbow" in the opening credits. The makers chose to use "Don't Fence Me In" instead. Interest in the writers of the latter song was increased substantially by the song's use over shots of a prison.