This was the first American film to be shot in Romania, particularly in the aftermath of the fall of Communism in Romania.
The song "Nightwing" by Swedish black metal band Marduk from their 1998 album of the same name is a cover of the main theme of Subspecies, and the song itself is about the main antagonist Radu Vladislas.
The Subspecies minions were originally going to be played by live actors in costume. Director Ted Nicolaou thought that the stuntmen were over-acting and that it didn't look well overall. Nicolaou then brought on FX artist David W. Allen to work with the subspecies stop-motion puppets.
Radu is named after Radu The Handsome, brother of Romanian prince Vlad The Impaler, who himself was the inspiration for the quintessential vampire Count Dracula.
Another deleted scene from the film featured Radu turning into a rotted corpse while asleep during the day. The director had the scene removed after realizing the effects didn't look very good.
Elements of the film, particularly the Subspeices minions, are actually recycled from an unmade film called "The Subterraneans", which in turn, was originally to have been filmed in the 1980s by producer Charles Band's previous studio, Empire International, in Rome.
The film's trailer also features a scene not retained in the final cut of the film.
A 10th Anniversary DVD, with a widescreen transfer supervised by J.R. Bookwalter, was planned for a late 1990s/early 2000s DVD release, but was cancelled for copyright reasons.