Despite the fact that this film states "Based on the novels 'The Howling I, II, and III' written by Gary Brandner", this film is in no way based on any of those novels, and is a sequel to the earlier Howling films in name only.
The film's original cinematographer was let go by the end of the first day of shooting, as he spoke virtually no English and so could not work effectively with Neal Sundstrom. Arledge Armenaki took over the role, despite only having a limited grasp of English himself at the time, but was able to communicate adequately well with Sundstrom, allowing filming to proceed.
Cedric Sundstrom was originally asked to direct by Clive Turner. He turned the offer down, as he was already committed to working on another film, but recommended his brother Neal Sundstrom, for the job. Neal took on the role, hoping to have a more positive experience on a film that he directed from the start, having taken over directing Space Mutiny (1988) partway through that film's production. Ultimately, he constantly found himself butting heads with Turner throughout filming.
"The Rebirth" takes place over the shortest period in its continuity out of the entire 'Howling' series. While most of the films take place over several days, Howling III (1987) and "The Rebirth" are the outliers - the former taking place over a period of two decades, "The Rebirth" in a span of less than twenty-four hours, while the opening scene takes place in 1489 so the movie technically takes place over 500 years.
The bus taking the visitors to the castle is a Kässbohrer Setra S208H in Malev (former Hungarian airline) livery. This bus, or the other one of two, is preserved at the Aeropark Budapest museum.