The extended laugh in the laboratory after Dr. Lester reveals his plan was not in the script, and was thought up by the editor as he was cutting. Because of that, Lurch can be seen going in to bite Dr. Lester's hand several times.
In the opening scene when the bat flies in and transforms into the vampire, on the far left of the screen one of the grips can be seen holding a broomstick with some fishing line attached to it.
Because there were a limited number of extras, when it came time for the massacre scene, some of the extras can be seen turning into zompires multiple times.
Though considered a gimmick, the subtitles for Vlad were necessary because through the actor's thick Grecian accent, and a mouth full of plastic fangs, it was impossible to understand what he was saying.