Director Sam Mendes designed the two girls' look to change over the course of the film, with Thora Birch gradually using less makeup and Mena Suvari gradually using more, to emphasize his view of their shifting perceptions of themselves.
When Lester throws the asparagus, he was supposed to throw it on the floor. The reactions of Annette Bening and Thora Birch are genuine.
According to his Oscar speech, screenwriter Alan Ball was sitting at the World Trade Center plaza when he saw a paper bag floating in the wind and was inspired by it to write the film, which was originally conceived as a stage play.
Kevin Spacey improvised everything he does in the car while his character is stoned and singing to "American Woman."
Since Thora Birch was barely 17 years old at the time she made the film and thus classified as a minor in the United States, her parents had to approve her brief topless scene in the movie, and they and child labor representatives were on the set for the shooting of it. "To me, [the nudity] made sense," Birch said of the scene. "It wasn't something that shouldn't be in there. It's something that would happen."