Both Michael J. Fox and Anthony Michael Hall turned down the role of Duckie.

Several actresses with bit parts in this film went on to bigger and better things. The English teacher is played by Margaret Colin ("Independence Day", "The Devil's Own"). Benny's snobby brunette friend in gym class is Gina Gershon, and the blonde girl eying Duckie at the very end is Kristy Swanson (credited as "Duckette").

There was an original ending filmed which showed Andie and Duckie ending up together. However, test audiences felt that Andie should end up with Blaine. Also, John Hughes felt that putting Andie with Duckie would make it seem as if the movie's message was that people from different backgrounds shouldn't get together. Therefore, the new ending with Andie kissing Blaine was shot.

When Andie is giving Duckie a ride home from the club, the song "If You Leave" starts playing. Duckie says, "I hate this song," and changes it. It's the same song that's playing at the prom at the end, when Duckie gives Andie up so she can chase after Blaine.

When Andie and Duckie are in the car, she stops in front of a large house and says it's her favorite. Later it's ironically shown to be Steph's house, where she attends the party.