Alfred Hitchcock was a big admirer of Salvador Dalí's work, and realized that no one understood dream imagery better. Producer David O. Selznick was opposed to using Dalí from an expense point of view, until he realized the marketing mileage that could be gained from such a hiring.

The dream sequence was designed by surrealist painter Salvador Dalí, and was originally supposed to run slightly longer. It included a scene in a ballroom with hanging pianos and still figures pretending to dance, followed by John Ballantyne (Gregory Peck) dancing with Dr. Petersen (Ingrid Bergman), who then turns into a statue. In order to create the illusion of a room of great size, little people were used in the background on a scaled-down set, which did not satisfy Alfred Hitchcock or Dali. The sequence was cut from the final movie, due to lack of time. Only part of it was filmed, and even less of it ended up in the released version.

Producer David O. Selznick wanted much of this movie to be based on his experiences in psychotherapy. He even brought his psychotherapist in on the set to be a technical advisor. Once, when she disputed with Alfred Hitchcock on the workings of therapy, Hitchcock responded, "My dear, it's only a movie."

Alfred Hitchcock referred to this movie as "just another manhunt wrapped up in pseudo-psychoanalysis."

Alfred Hitchcock was disappointed with the limits of Gregory Peck's facial expressions. According to Peck, "I couldn't produce the facial expressions that Hitch wanted turned on. I didn't have that facility. He already had a preconception of what the expression ought to be on your face, he planned that as carefully as the camera angles. Hitchcock was an outside fellow, and I had the Stanislavski training from the Neighborhood Playhouse, which means you work from the inside."

The snow falling on John Ballantyne (Gregory Peck) and Dr. Petersen (Ingrid Bergman) during the skiing scene was actually cornflakes.

Although this movie is in black-and-white, two frames where the gun shot goes off while pointed at the camera are tinted red.

Early versions of the script used the words "sex menace", "frustrations", "libido", and "tomcat" in scenes involving the character of Mary Carmichael. These were eliminated when Product Code administration director Joseph I. Breen strongly objected.

One of the first Hollywood movies to deal with psychoanalysis.

According to Alfred Hitchcock's biographer Donald Spoto, retakes director William Cameron Menzies was disappointed at what he considered an unappealing dream sequence, and asked to remain uncredited for it. When the sequence received critical and audience acclaim, Hitchcock was happy to take the credit.

After Alfred Hitchcock had suggested "Hidden Impulse" as a title, studio secretary Ruth Rickman came up with the title Spellbound (1945), which tested well in a pre-release survey.

Miklós Rózsa's score in this movie inspired the career of movie composer Jerry Goldsmith. Gregory Peck liked the score so much that in his last years, he used it in his one-man touring lecture show, "An Evening with Gregory Peck."

The first preview took place on September 27, 1944, after which producer David O. Selznick deleted an opening montage showing treatment of mental cases. After principal photography was completed, Selznick was involved with sound re-recording of the dialogue and the editing, eliminating about fourteen minutes of the movie.

Originally released with an overture before the opening credits, and exit music after the end title.

The Dali dream sequence was shot originally to run twenty minutes, but ended as only two. Alfred Hitchcock originally wanted Josef von Sternberg to shoot it, but it was ultimately directed by William Cameron Menzies.

Screenwriter Ben Hecht consulted many of the leading psychoanalysts of the day.

The dream sequence was produced by "Poverty Row" studio Monogram Studios. Its initial efforts kept getting rejected by producer David O. Selznick, until he hired production designer William Cameron Menzies to oversee the production. Alfred Hitchcock was barely involved.

Producer David O. Selznick originally wanted Joseph Cotten, Dorothy McGuire, and Paul Lukas in the roles ultimately played by Gregory Peck, Ingrid Bergman, and Leo G. Carroll. He also briefly toyed with the idea of bringing Greta Garbo out of retirement to play the role of Dr. Constance Petersen.

The Shakespeare quotation at the start of this movie is an abbreviated version of something that Cassius said to Brutus in Act 1 Scene 2 of "Julius Caesar". The full quotation is "The fault, dear Brutus, is not in our stars, but in ourselves, that we are underlings."

Producer David O. Selznick wanted Miklós Rózsa to swell the orchestra from fourteen violins to twenty-eight, as he had liked the effect that that had brought when Franz Waxman did it while scoring Rebecca (1940). In addition, Selznick was dissatisfied with Rozsa's musical cue for the skiing sequence, and replaced it with one from Waxman's score for Suspicion (1941).

Composer Miklós Rózsa hated working with producer David O. Selznick.

Alfred Hitchcock's first choice for the role of John Ballantyne was Cary Grant. His second choice was Joseph Cotten.

Alfred Hitchcock persuaded producer David O. Selznick to buy the rights to the novel for $40,000.

In a few scenes it can slightly been see that Gregory Peck is quietly moving his lips while Ingrid Bergman is delivering her lines, just before his lines. (looks like he reciting her lines, something young actors do from pressure or when they dont want to forget when they're own lines)

The only Best Picture Oscar nominee that year to be also nominated for Best Special Effects.

The then relatively obscure Ruth Roman sought a role in the film. Roman played the female lead in Alfred Hitchcock's later film Strangers on a Train (1951).

James Flavin is in studio records and casting call lists for this movie, but he did not appear, or was not identifiable.

Michael Chekhov was the only Best Actor in a Supporting Role Oscar nominee that year that was from a Best Picture nominated movie.

Alfred Hitchcock directed a one hour radio version starring Joseph Cotton and Mercedes McCambridge in the principal roles, NBC's Director's Playhouse, 1/25/51.

Features Michael Chekhov's only Oscar-nominated performance.

The only Best Picture Oscar nominee that year not to be nominated in either of the lead acting categories.

Included among the "1,001 Movies You Must See Before You Die," edited by Steven Schneider.

This film is part of the Criterion Collection, spine #136.

Included among the American Film Institute's 2001 list of 400 movies nominated for the top 100 Most Heart-Pounding American Movies.

Opening credits: The events and characters depicted in this photoplay are fictitious. Any similarity to actual persons, living or dead, is purely coincidental.

Servants cutting right through the eyes painted on the drapes in the dream sequence is the reference to slitting the eye with the razor in the notoriously famous scene from Un Chien Andalou (1929). Notably, the dream sequence was based on designs by Salvador Dalí who was also the screenwriter of "Un Chien Andalou" and came up with the idea for the notorious scene after the director Luis Buñuel told him about this dream.

Alfred Hitchcock: (At around forty minutes) Coming out of the elevator at the Empire Hotel carrying a violin case and smoking a cigarette.

The gun blast in the end is hand painted. Alfred Hitchcock used a form of hand coloring for the orange-red gun blast at the audience.

The shot where the audience sees the killer's view down a gun barrel pointing at Petersen was filmed using a giant hand holding a giant gun, to achieve the proper perspective.