Alfred Hitchcock adapted Psycho from a story by author Robert Bloch, who had modeled the character of Norman Bates after Ed Gein, who is suspected to have killed his victims between 1954 and 1957. In the asphyxiation death of his brother Henry (who was verbally critical of their neurotic-controlling mother) in 1944, though the supposedly harmless young Gein was quickly dismissed as a suspect, it's believed that he was guilty of that crime too. Other characters very loosely based on Gein are Buffalo Bill in "The Silence of the Lambs" (1991) and Thomas Hewitt in "The Texas Chainsaw Massacre" (1974). The main similarities to Gein that appear in "Psycho" include the feminine qualities of Norman Bates and the disturbingly strong attachment to the cruel domineering mother.

Apparently Janet Leigh has not taken a shower since first watching Psycho, feeling safer in a bath.

Psycho is the first movie to show the bathroom with the toilet (which was deemed inappropriate beforehand) and even with it flushing.

The film somewhat stirred controversy when it was released because it was the first time that a leading actress' (Janet Leigh) character dies during the first third of the film. Before Psycho, the leading actress' character either lives throughout the film or dies at the end. Her character never dies early in the film.

Anthony Perkins did not participate in the shower scene. At the time, he was in New York preparing for a play on stage.

In the opening scene, Marion Crane is wearing a white bra because Alfred Hitchcock wanted to show her as being "angelic." After she has taken the money, the following scene has her in a black bra because now she has done something wrong and evil. Similarly, before Marion steals the money, she has a white purse; after she's stolen the money, her purse is black.

During the theatrical release of Psycho, no one was allowed in the cinema after the movie started because Marion (played by Janet Leigh) dies quite early on in the movie.

Alfred Hitchcock makes a cameo in the film during the scene when Marion Crane walks into her office. He is standing outside the office on the audiences' right corner.

The three letters on the license plate of the car which eventually ends up in the swamp are NFB. The represented the initials of Norman Francis Bates.

Sales of showers plummeted after this movie was released.

Alfred Hitchcock didn't want to have the ending of the movie given away. So after buying the rights to make the movie, he bought every copy of the book that he could find so that no one would be able to read it and know what happens before watching it.

When the original Psycho was first released, a concerned man wrote to Alfred Hitchcock to say that since watching Psycho, his wife refused to shower or bath. Hitchcock promptly wrote back saying "sir, have you ever considered taking your wife to the dry cleaners?"

Janet Leigh spent three weeks on the set. A whole week was devoted to the infamous shower scene.

Psycho was filmed with a TV crew not a film crew

The security guard who gives "mother" a blanket at the end of the movie has the door opened for him by a young Ted Knight.

The blood in the infamous shower scene is actually chocolate syrup.

The design of Norman Bates' house was based on the Edward Hopper painting "The house by the railroad" painted in 1924. Hitchcock described the Gothic architectural style of the house as "California Gingerbread."

Though Psycho is a Paramount Picture, it was filmed at Universal Studios.

There are many references to birds in this film, few examples are: Marion's surname is Crane which is a bird, the movie is set in Phoenix which is a legendary bird which rose from the ashes, there are stuffed birds in Norman Bates' parlour and his hobby is stuffing them, there are numerous pictures of birds through out the hotel, and Norman makes many references to birds such as telling Marion she "eats like a bird." Hitchcock was fascinated with birds, even making another horror movie called "The Birds" (1963).

Psycho was made with a budget of under $1,000,000.