Derek's repetition of the line "But why male models?" for the second time in the cemetery scene was an ad-lib by the actors; Ben Stiller forgot his line and simply repeated the earlier line again, and David Duchovny ran with it and gave him a straight answer.
Bret Easton Ellis, author of the 1998 book Glamorama, about a dimwitted male model who finds himself embroiled in a terrorist ring with roots in the fashion industry, sued Ben Stiller following the release of Zoolander (2001), citing copyright infringement. The case was later settled out of court.
The film has been banned in Malaysia because of the use of fictional Malaysian Prime Minister as the subject of assassination. It was originally also banned in neighboring Singapore, but the ban has since been lifted.
While trying to be farcical, the film is actually quite accurate regarding the modeling industry. Even the quick scene of the two sets of bunk beds at Derek's apartment is factual; Cindy Crawford and Jules Asner shared a similar bunkroom during the early days of their modeling careers.
When Derek first gets to Hansel's pad and Hansel asks Ennui to get him some of the special tea, there is a picture in the background of Hansel holding two tires - this is a copy of a famous Herb Ritts photo from 1984, "Fred with tyres".