The house seen in the movie in real life doesn't and never actually did exist. The film-makers could not find a suitable mansion to use for the film so at a cost of around $200,000, the production had a Victorian gothic mansion facade attached to the front of a much more modern dwelling in a Vancouver street. This construction was used for the filming of all the exteriors of the movie's Carmichael Mansion. The interiors of the haunted house were an elaborate group of interconnecting sets built inside a film studio in Vancouver.
Director Peter Medak said he was initially intimidated by stories of actor George C. Scott being difficult to work with. The only trouble Medak had with Scott on the set was when production managers accidentally knocked over a chess board on which Scott had been playing a game against himself for over two weeks.
George C. Scott learned how to play the piece of classical music that he plays on piano for the college students.
Actors Trish Van Devere and George C. Scott were married to each other in real life. Publicity for this picture stated they had worked together seven times in their (then) eight years of marriage. They had been together in six movies (one for television) and one stage play.