DD was 5. Caught her watching "I Am Legend" on HBO one day and "The Invasion" on another, which she thought were "awesome." So I figured there should be no problem with "Twilight." She loved it, has listened some to the audio books, and has seen "New Moon." She even had a NM birthday for her 6th. People get a real kick out of a 6 year old explaining the books, movies, and the relationships of the characters.