The production was shot without a completed script. As a result, there were many delays and arguments over what to shoot. James Gandolfini admitted, in a behind the scenes interview, that most of the film was "improvised".

Jon Favreau was offered a chance to direct, but made Elf (2003) instead.

John Wight, who worked on the film as Ben Affleck's stand-in, wrote a devastating depiction of what the filming was like in his book "Dreams that Die: Misadventures in Hollywood".

James Gandolfini was only ten years and two months older than Christina Applegate, who played his daughter in this film.

The original Christmas 2003 release date was pushed back ten months, to avoid competing with another Ben Affleck film, Paycheck (2003). Because of this, there's a 2003 calendar hanging in Brian's bedroom, near the door.