Continuity: When Katherine Heigl and her sister are having a fight, her sister throws a portable phone onto the couch. When you see the couch again a few seconds later the phone has disappeared.

Audio problem: Right at the start of the movie when Jane meets up with her friend on the street, her friend says something like, "Let's go", but her mouth doesn't move.

Continuity: When the sisters are at the baseball game and Katherine Heigl is eating french-fries there is a shot that shows her taking a bite of the french-fry but when the shot changes she has a whole fry in her hand. Submitted by Disney-Freak

Continuity: When Jane is tying George's tie, the part around his collar goes from being seam-side out to in to out again between camera angles.

Continuity: At the end of the movie, the Commitments article states that there were 27 bridesmaids after it is stated that all the women Jane was a bridesmaid for were bridesmaids at her wedding. If that's the case, then there were really 29 bridesmaids, since in addition to the 27 bridesmaids from previous weddings, her unmarried sister and best friend were also bridesmaids.