Trivia: There are many references to the number 237 in the movie. For instance, this is the number of Red's cell, and these digits are on Andy's prison I.D. This number makes appearances throughout Steven King stories, the most famous one being the room where the murders take place in "The Shining".
Trivia: The Humane Society had to be present for the scene when the maggot is feed to the bird, Jake. The Society said it was cruel to the maggot, so it had to get a maggot that died of natural causes before the crew could shoot it.
Trivia: Andy and Red's opening chat in the prison yard, in which Red is pitching a baseball, required nine hours to shoot. Morgan Freeman pitched the baseball back and forth for the entire nine hours of shooting without a single word of complaint. He came back to the set the next day with his left arm in a sling.