Continuity mistake: When the girls are eating lunch in the desert, and the hot Australian guy pulls up and chats the girls up, they show where he came from and the tire tracks in the sand. However, the tracks don't go back that far, so the guy really wasn't driving all around the sand dunes like Carrie's narration says.
Continuity mistake: When Carrie goes to the changing room with Stan, her boutonnière is labeled Carrie Preston. When she questioned this, Stan says the wedding planner said all couples should be listed by their married name. But in the shot of the program she is listed as Carrie Bradshaw under the best man.
Continuity mistake: In the conclusive, third act of the film, Charlotte and Miranda are sipping drinks and discussing the difficulties of motherhood. During the scene, Charlotte's drink varies from nearly empty to entirely full and then back to being nearly empty over the course of only a few frames.
Continuity mistake: When Big comes home from work and Carrie is dressed to go to the premiere, Big has brought dinner home in a bag. Carrie points at the bag and asks what it is. When Big is answering her, her arms are back down but when the shot goes back to her, her hand is pointing again.