Based on the true story of Anneliese Michel, a young German woman who suffered the same fate as the fictional Emily Rose in the 1970s. The original inspiration for the movie was a book titled "The Exorcism of Anneliese Michel" by Dr. Felicitas Goodman. She was the anthropologist called in as an expert on possession. However, the original was heavily adapted for cinematic purposes. Madeline Zima was considered for the role of Emily Rose.