Liam Neeson nicknamed Catherine Zeta-Jones "The Welsh Gazelle", because they repeated a running take time after time, and he couldn't keep up with her.

Stephen King wrote the first draft of the script. When this fell through, he re-worked it into Rose Red.

This second adaptation of the book was going to be titled "The Haunting of Hill House", which was the original novel title. It was shortened back to "The Haunting" to avoid confusion with House on Haunted Hill (1999).

The house used in the film is located in Grantham, England, and is owned by the University of Evansville (Indiana). It is used by students that study abroad.

Liam Neeson is afraid of heights, so his fear, when he was dangling off the flight of steps while trying to save Nell, required no acting.

This isn't a remake of Robert Wise's classic, as the production company did not have the remake rights. They were not allowed to replicate even one shot from the 1963 film. Instead, it is a new adaptation of Shirley Jackson's novel.

The creaks and moans heard throughout the house were recorded and played during filming in order to get a more natural expression of fear out of the actors.

The tagline for this movie "some houses are born bad" is also a line that Dr. Joyce Reardon says in the Stephen King made-for-television series Rose Red (2002).

The outside of Hill House, as well as some interiors were filmed in Harlaxton Manor, in England.

At the time of its release, it was widely rumored that Steven Spielberg either directed some scenes or participated in post-production because he didn't like the rough cut he saw. This was, however, never confirmed.

Several of the sets depicting Hill House were built in the hangar that housed The Spruce Goose, the mammoth airplane built by Howard Hughes.

An alternate ending was also filmed, in this version, Dr. Marrow (Liam Neeson) writes a book regarding the results of his fear study and is dedicated to Luke (Owen Wilson), Nell (Lili Taylor), Rene Crain (Kadina de Elejalde), and Carolyn Crain (Hadley Eure). He even mumbles that they are immortal. Theo (Catherine Zeta-Jones) pays a visit to the peaceful Hill House, seeking both Nell and happiness.

The project was originally with Dimension films, with Wes Craven attached to direct.

Cinematographer Caleb Deschanel was originally attached to shoot the movie, and even completed some of the filming, but dropped out due to creative differences.

Michael Tolkin did an uncredited re-write on the script.

This was the first film for uncredited Executive Producer Samuel Z. Arkoff in almost fifteen years. It also gave him a chance to work with his daughter, Donna Roth, who was one of the producers.

The film cast includes one Oscar winner: Catherine Zeta-Jones; and five Oscar nominees: Liam Neeson, Owen Wilson, Virginia Madsen, Todd Field, and Bruce Dern.

The set designed by Eugenio Zanetti and built in the Spruce Goose hanger was one of the largest interior sets ever built.

The part of the big lion head in the fireplace was originally played by a large green ball.

The small car that Luke tries to crash through the gate is a 1974 AMC Gremlin.

In this movie, Owen Wilson plays a character named Luke, his brother's name in real-life.

The official Spanish title for the film is "The Haunting (La Guarida)". Translated to English, it would be "The Haunting (The Lair)".

Even though he's uncredited as executive producer Steven Spielberg casted Catherine Zeta Jones (Theo) five years later, in The Terminal (2004).

Voice-actors in this movie Courtland Mead and Travis Tedford appeared in The Little Rascals (1994).

The shooting script used during filming saw more scenes with Hill House's caretakers, the Dudleys. In one scene, when Dr. Marrow (Liam Neeson) is talking to Nell (Lili Taylor) alone in the greenhouse, Mr. Dudley (Bruce Dern) enters and tells Nell about where Hugh Crain's (Charles Gunning's) first wife Rene (Kadina de Elejalde) hung herself before he goes off to clean the paint letters from the Hugh Crain portrait. In another, after Nell finds out Dr. Marrow isn't behind the creepy incidents at Hill House, she walks out of the dining room to the main hall and sees the Dudleys about to leave for the day. Mr. Dudley at first holds the door open as an invitation for her to go with them. When Nell doesn't join them, Mrs. Dudley (Marian Seldes) smiles and she shuts the door as she leaves with her husband, which locks behind her.

Eleanor "Nell" Vance (Lili Taylor) and Luke Sanderson (Owen Wilson) are the two guests who die in Hill House, and are the only characters to close the main hall doors, that are later used to trap the ghost of Hugh Crain (Charles Gunning). Nell closes one of the doors when she tells Theo (Catherine Zeta-Jones) about purgatory, and later Luke shuts one of the doors, to give Nell some privacy with her tests, when he leaves.

The ghost of Hugh Crain was originally supposed to emerge from the fireplace and try to attack Nell. In the theatrical cut, Hugh Crain's ghost comes out of the defaced portrait and hovers down the staircase to Nell.

(At around six minutes) In the movie, Dr. David Marrow talks to his boss Malcolm (Michael Cavanaugh) about his research on the dynamics of fear. In the shooting script, Malcolm allows Marrow to go to Hill House because it will give him the study and results he needs for the last chapter of his book titled "Fear and Performance". In the script's alternate ending, Marrow publishes the book and dedicates it in memory of those who died in Hill House: Rene Crain, Carolyn Crain, Eleanor "Nell" Vance, and Luke Sanderson. David Marrow's book being published is cut out of the movie, though Malcolm does say "fear and performance" to David when originally trying to talk him out of doing his research.

In the theatrical trailer, there is a scene where Nell asks Theo if she ever kept something to herself because she was afraid and Theo says, "All the time." This is taken from a deleted scene mentioned in the original shooting script used during filming where Theo and Nell are in Theo's rooms, having drinks and Theo is painting Nell's toenails.

In the script, when Hugh Crain's ghost is closing the doors of Hill House to prevent the guests from leaving, Nell watches and repeats Mrs. Dudley's line, "In the night. In the dark.", in-between scenes where doors to the house slam shut and lock on their own. In the film, Nell says "In the dark" ahead of Mrs. Dudley when she repeats her quote to Theo in her bedroom for comedic effect.

In the original shooting script, Dr. David Marrow's first name was Jim. The name David is taken from an omitted character from the script named David Watts, who was a guest Marrow invites to Hill House for the study. The absence of Watts takes up most of the shooting script when Nell sees Watts' car drive up and she later finds the keys to his Toyota by the fireplace, but Watts himself doesn't arrive inside the house, and the guests split up to look for him. Near the end, when Marrow, Theo, and Luke look for Nell when she re-enters Hill House, they find the dead body of Watts held in the hand of the man statue in the greenhouse pool.

Deleted scenes shown in theatrical trailers and television commercials for this movie, but not included in the final cut of the film, include a scene where Nell (Lili Taylor) and Theo (Catherine Zeta-Jones) open up doors to the house while exploring, and they find brick walls in the doorway to prevent them from entering, an effects shot with Hugh Crain's Ghost exploding out of the fireplace, and a scene with Theo in Nell's bedroom, shortly before Dr. Marrow (Liam Neeson) admits the truth about his experiment, with Theo saying "As soon as I turn out the light, my heart starts pounding."

In the Behind the Scenes Feature, Owen Wilson says that during the scene where he is beating the painting with a candlestick, a piece of it came off and hit him in the face. He had to get stitches.