The idea of John Tucker wearing a thong was not in the original script. Originally, Kate talked him into shaving his head. Betty Thomas thought making him wear a thong was funnier. While shooting, the extras were actually taking pictures of him with their phones.
Ashanti had multiple concerts she had to perform during the making of the film, while Sophia Bush was also committed to shooting One Tree Hill (2003).
Since shooting took place during the actual school year in an existing high school, the crew had to ask students for permission to use and re-dress their lockers for shooting.
Jenny McCarthy plays Brittany Snow's mother even though the two actresses are only 14 years apart in real life.
In the script, the school didn't have a specific mascot. But while filming on location at an actual high school, the film adopted their mascot, the Kodiaks.
While shooting, the sound of the extras' flip-flops proved too distracting, so Betty Thomas made most of them change into tennis shoes.
Director Betty Thomas referred to all the actors by their characters' names, since, she claims, she couldn't remember their real names, and she wanted to think of them as their character. When she forgot their characters' names, she'd simply refer to them as "person."
Director Betty Thomas' dogs, Jackie and Rico, were constantly on set during filming and had to be cut out of several scenes.
Scott and Kate make reference to the Cheap Trick song "I Want You To Want Me," and at the end of the movie, the newer version of the song, performed by Letters to Cleo, can be heard in the background.
In the script, the A.V. room in which the girls concoct their plans to destroy John Tucker was referred to as "The War Room."
Letters to Cleo performed the song "I Want You to Want Me" at the end of the 1999 film "10 Things I Hate About You."