The real Perron family visited the set of the film.
The film was shot in chronological order.
The production team also built a fifty-foot tall tree for the film.
Eight generations of families lived and died in the house before the Perrons moved in. Andrea Perron suggested that some of the spirits from the families never left. Deaths included two documented suicides, a poisoning, the rape and murder of an 11-year old girl, two drownings, and four men who froze to death. Most deaths occurred within the Arnold family, from which Bathsheba Sherman was descended.
The film was given an R rating by the MPAA. The filmmakers had thought the final cut had a chance of getting the more-box office friendly PG-13 rating, and asked the ratings board for clarification. The MPAA said simply that the film was so scary that there were no cuts or edits possible that would make it a viable PG-13 film; the filmmakers did not want to alter the film's tone and accepted the R rating without any appeals.
Lorraine Warren: (at around 44 mins) Elder woman in the front row of the classroom when Carolyn is listening to the Warrens' presentation.