Factual errors: Playboy Bunnies were waitresses at the Playboy Club chain. Playmates are nude models.
Continuity: During the Aztec party, when Natalie steps out of the water following her "sacrifice", she is completely dry.
Continuity: When Shelly gets out of jail and is sitting on the curb doing her make-up some college girls walk by discussing a party. The girls are walking behind Shelly and towards camera right. When Shelly spies on them through her make-up mirror, the girls are walking towards the right of the mirror when they should be walking towards the left.
Continuity: During the scene when the sorority girls are on the lawn talking about boys, Emma Stone's character Natalie has her glasses on for most of the scene, but for one shot back to her they are off, and then the cut back scene they are magically back on again without her arms even moving.
Continuity: In the sorority car wash scene, Natalie deliberately turns the water hose on her shorts. At first, the wet area is very large and soaked but when the camera cuts away for a fraction of a second and cuts back to her, the wet area shows just a few traces.
Incorrectly regarded as goofs: It is not impossible for Ashley's friend to become a zeta at the end because she's already in a sorority: it is only impossible to be in two sororities at once. Most organizations have ceremonies or require letters of intent from sisters who no longer want to be affiliated with their old sorority.
Continuity: When the girls from the Phi Iota Mu Sorority release the pig into the Zeta's house Joanne, Rumer Willis' character, falls off her chair 2 or 3 times without ever been seen getting back onto the chair.
Errors made by characters (possibly deliberate errors by the filmmakers): During dinner, Shelly mentioned her butt to Oliver several times and even mentioned that she didn't have any tan lines. However when Shelly was walking around the house naked earlier in the movie, tan lines were definitely visible.