To appease the producers, who wanted to soften the dramatic ending a bit, an alternate version of the ending was storyboarded, with Somerset saying that he "wants out", and killing John Doe, thereby preventing Doe from winning, and Mills from ending up in jail. In the mean time, the crew shot a test ending, which is basically the theatrical ending without some of the dramatic shots. This finale was so well received in screenings that it convinced the producers to go along with it, and not even film the alternate ending.
Director Gus Van Sant at one point asked Matt Damon and Ben Affleck to rewrite the script so that Chuckie is killed in a construction accident. Damon and Affleck protested, but reluctantly wrote the scene in. After Van Sant read it, he agreed that it was a terrible idea.
When a Fight Club member sprays the priest with a hose, the camera briefly shakes. This happens because the cameraman couldn't keep himself from laughing.
After the copyright warning, there is another warning on the DVD. This warning is from Tyler Durden, and is only there for a second. "If you are reading this then this warning is for you. Every word you read of this is useless fine print is another second off your life. Don't you have other things to do? Is your life so empty that you honestly can't think of a better way to spend these moments? Or are you so impressed with authority that you give respect and credence to all who claim it? Do you read everything you're supposed to read? Do you think everything you're supposed to think? Buy what you're told you should want? Get out of your apartment. Meet a member of the opposite sex. Stop the excessive shopping and masturbation. Quit your job. Start a fight. Prove you're alive. If you don't claim your humanity you will become a statistic. You have been warned... Tyler"