A number of pieces of the set, including those used for the rooftop chase, were sold to the production of The Matrix (1999) at the end of shooting.
There were many deliberate anachronisms to give the viewer a feeling of confusion about the time period of the film.
New Line Cinema forced Alex Proyas to include the opening narration by Kiefer Sutherland, which gives away several plot reveals. Alex Proyas objected to it, saying it was unnecessary, and he subsequently removed the narration from his director's cut.
Has one of the shortest Average shot lengths (ASL) of any modern narrative production at 1.8 seconds. This means there is a cut almost every 2 seconds.
An over-sized version of Dr. Schreber's syringe (roughly a yard long) was built for the close up shots of the needle being extended so that its surface details could be seen clearly.