All of the children did their own singing in the audition scene on stage for the school play, except Greg Heffley.
While the studio was deciding where to film the movie, they said they were looking for the "perfect American town." Ironically, they found the perfect American town in Canada.
Before Zachary Gordon was cast as Greg Heffley, he was celebrating his eleventh birthday. His birthday wish was to get the part.
The character of Angie was not in the book. She was created exclusively for the movie.