Claire Bloom was intrigued to the play the role of a woman who was attracted to another woman. She said she got along with everyone on the set, except for Julie Harris, who tried everything to avoid her and not talk to her. At the end of the shoot, Harris went over to Bloom's house with a present and explained that the reason she had kept to herself was to stay in character, because Harris' role in the film was that of an outsider that none of the others understand or will listen to. Bloom was happy to hear the real reason behind Harris' behavior, since Bloom stated that she really liked Harris and could not understand what she herself had done wrong to be treated like that by her co-star.
Director Robert Wise read a review of Shirley Jackson's novel "The Haunting of Hill House" in Time Magazine and decided to get the rights to the novel. He later met the writer herself to talk about ideas for the film. He asked her if she had thought of other titles for the novel, because the title would not work for the film. She told him that the only other title she had considered was simply "The Haunting", so Wise decided to use it for the film.
In the 50th issue of Scarlet Street magazine, Julie Harris revealed that she wished she could go back and play the character differently. "Well, I would've been odder looking as Eleanor," she said. "I think she was too ordinary. I just wanted to be -- odder."
Nelson Gidding's initial concept for the script was that Eleanor had experienced a nervous breakdown and had been hospitalized, and that the house was the hospital, the other characters were staff and patients, and the booms and knockings were the result of shock treatments. The entire story would have been inside the head of a mentally ill woman. However, upon discussing this with author Shirley Jackson (who simply regarded it as a haunted-house story), he decided to backpedal on that idea, but still emphasized Eleanor's crumbling sanity in his final script.
The exterior of Hill House in the film was not a set, but an actual house (Ettington Park Hall Hotel, Stratford Upon Avon), although all the interiors were carefully designed sets on sound stages. While shooting exterior night scenes on location at the real house, Russ Tamblyn has shared a story of having chosen to take a stroll through a cemetery at the rear of the property and having had an experience nearly as terrifying as the film itself. You can hear his story on the commentary track included on the DVD of the film.
Robert Wise had been on a contract with MGM and owed them one more film, so he brought "The Haunting" to them. They would only give him 1 million dollars to shoot the film, and Wise insisted that he needed a bigger budget. In the end he brought the project over to MGM in London, where they were willing to pay him 1.1 million, so he accepted and decided to do the film in England.
Robert Wise had seen Julie Harris in a play and decided she was perfect for the leading role. She later confessed that shooting the picture had been very hard on her. She saw her character, Eleanor, in a different way than director Wise but didn't feel it was her place to disagree, so playing the part was a struggle for her. Still she claims Wise was a perfect gentleman and they remained friends for decades.
The names on the blackboard in Dr. Markway's office are all friends or family of writer Nelson Gidding. Albert Trepuk was his stepfather, Charles Stern, Ruth Murray, Rufus Matthewson, and Paul Kirschner were friends, and Joshua Walden was his then 14-year-old son.