Alternate versions

On the Universal DVD, Norman can be heard (not seen) screaming "I'm Norma Bates!" as Sam Loomis rushes in to stop him from murdering Lila. The scream is not present in at least some release prints.

For the original theatrical release, the UK censors cut the shower scene. All later video/DVD releases reinstated this footage, but lacked the cuts implemented in America.

In the UK, the film was originally distributed by Universal Pictures and cinema and VHS releases replaced the Paramount Pictures logo with the Universal one. DVD releases have the Paramount logo as seen in the US version.

5.1 Blu-ray remix adds a bunch of new sound effects like background ambiance and new rain sounds. It also alters a bunch of other sound effects like doors closing and the shower noises. The original mono mix is included as a second option.

The U.S version that was previously released on home media for the longest time was actually an edited version of the movie. It is missing a shot from the shower undressing scene, a lingering close up of bloody hands, and additional thrusts of the knife for the killing of Arbogast inside the house. The movie was edited for content in 1968 when the ratings system was first established (the movie initially went in without a rating in 1960 due to no such system existing yet) to obtain an R rating. This version was seen on German TV but was never released on home media until the 2015 Blu-ray release from Turbine Media in Germany, which has the original 1960 uncut version. In 2020, Universal released their own uncut Blu-rays and 4K UHD-BDs worldwide and this was one of them.

USA versions of this movie, had two aspect ratios, both with the running time of 108 minutes and 51 seconds. The original theatrical matte was 1.85:1 but the 35mm negative was "Open Matte". Originally shot in full frame 1.33:1 (Open Matte) with the contractually required intention that each movie theater would only ever show the movie film in the studio recommended 1.85:1 aspect ratio. Achieved by masking off the frame during projection, by using a 1.85:1 Projector Aperture Gate Plate. All of the image located outside of the area intended to be shown, is fully blocked. Worldwide when broadcast on TV in the 70s 80s 90s the unmatted full frame 1.33:1 version was shown (Open Matte) which was similar in shape to the original format of TV screens, the original television standard was 1.37:1 (4:3) Aspect Ratio. VHS NTSC videotapes and the 1979/1981 DiscoVision (MCA) Laserdiscs and the 1984/1988 MCA Home Video Laserdiscs were issued in the full frame 1.37:1 (4:3) version, matching the original television standard Aspect Ratio. DVD and Blu-ray releases only have the Aspect Ratio 1.78:1 version. The full frame 1.37:1 (4:3) version is not available on DVD and Blu-ray and 4K UHD-BDs releases. MCA/Universal Home Video Laserdiscs widescreen version with Aspect Ratio 1.78:1 were issued from 26 May 1998. At the time of Laserdisc manufacture in 1984/1988, the studio claimed that the original 35mm negative was lost. Laserdisc version has some of the shower scenes zoomed-in ever-so-slightly, because the studio used the only remaining available source material, a cleavage-hiding TV print matte. VHS NTSC videotapes are not cropped for these scenes. However the famous shower scene, permanently has the 1.85:1 aspect ratio (Hard Matte) on the original negatives, which was created by permanently blacking the top and bottom of the frame. 60th Anniversary Blu-ray and 60th Anniversary 4K Ultra HD issued September 2020, now has the original version, plus a 13 second longer restored version. Original 1960 version is 108 minutes and 51 seconds. Restored version is 109 minutes and 04 seconds. The famous shower scene is identical in both versions (2 minutes and 38 seconds). From 44:44 minutes - Marion does not know that Norman Bates is watching her, as she is undressing for the shower. Two second shot where she removes her bra, but this is an angled shot where her breasts can not be seen, so there was little need to edit. Normans eye closeup, and dropping off her bra is missing (5 seconds). From 53:06 minutes - After the homicide, Norman Bates stares at the blood on his hands and takes much longer washing his hands. Normans bloody hands are visible longer (1 second) and Norman went to bathroom with his bloody hands (4 seconds). From 77:47 minutes - The detective Martin Balsam is attacked and falls down the stairs. After the detective fell down the stairs, and whilst he is lying on the floor, Mother attacks him with the knife, an additional two times (3 seconds).

According to information collected by the American Film Institute, the Catholic Legion of Decency demanded three specific cuts before it would give Psycho its "B" rating ("morally objectionable in part for all") instead of a "C" ("Condemned"). The scene of Marion undressing as Norman watches her through the peephole, the closeup of Norman's bloody hands while cleaning up after Marion's death, and the shot of the knife coming down on Arbogast would all have to be shortened. The film was given a "B" rating, which suggests these cuts were made before the initial US theatrical release. However, the footage corresponding to these cuts was later seen in some German TV broadcasts and was later incorporated into the "uncut" version on the German Blu-ray release from Turbine Media and Universal's own 4K remastered UHD and Blu-ray releases. Though these slightly longer prints had evidently been distributed at some point (at least in Germany), it's unclear if they actually played in theaters in 1960.

The Netflix print is in the 4:3 (1.33:1) aspect ratio in which the movie was originally filmed. It features the old Universal logo from the 1960s-80s in black and white.

In New Zealand, the film was originally censored for an R18 rating, toning down violence and horror:

• "Substantially reduce scene of woman being killed while under shower to show initial stab, followed by her hand clutching curtains."
• "Reduce views of killer's bloody hands, and views of blood on walls."
• "Reduce views of Arbogast being killed to initial stabbing, followed by view of his bloody face which should be retained, but not repeated stabs that follow."
• "Reduce views of skull of mother to first shot only, and reduce screaming of Lila."

The rating was reduced to R16 in 1977, and the cuts waived entirely in 1992.

According to his 2004 book "Irish Film Censorship: A Cultural Journey from Silent Cinema to Internet Pornography," the Irish film historian and lecturer Kevin Rockett documented that the distributors of "Psycho" originally did not appeal the Irish censor's ban on the film in 1960; however, when the distributors of Peeping Tom (1960) successfully appealed that film's banning and the already-cut UK version was allowed to be distributed in Ireland with an "Over 18s" rating with only one additional cut, they resubmitted a shorter version of the film to the Irish Film Censorship Office (IFCO) in 1961. According to the book, the version resubmitted eight months after its initial ban was forty-seven feet shorter in film length. The official Film Censor at the time, Liam O'Hora, noted that the film was initially "strictly for adults," but had been altered to "make it suitable for exhibition for children." Still, O'Hora requested additional cuts before approving the film for general exhibition. The version of the film which was finally released in Irish cinemas in 1961 had the following alterations:

• Marion's line to Sam, "I'm late, and you have to put your shoes on," in the opening hotel room scene was cut.
• Two shots of Norman spying on Marion through a peephole as she is changing were cut, but the shot of Norman spying on her after she had put on her dressing gown remained.
• The shower scene was primarily left intact, but O'Hora took objection to some scenes of blood. The shot of Marion sinking against the wall after being stabbed was shortened, as was the shot of blood going down the shower drain. O'Hara's directives to the distributors were, "No gobbets of blood, etc. Cut shots of blood flowing in bath water. Flowing water OK when blood ceases."
• Directly quoting Rockett's book, "Later, Norman comes down from the house to clean up the mess in the cabin, but, as he leaves, he twice says 'blood' to his 'mother'. Because we hear, and do not see, the blood, these words are allowed. Thus, the Censor decreed, 'Cut shot of Norman's hands saturated with blood and subsequent washing. Cut shots of blood in bath etc.' The effect, then, is not to erase the murder and show it in all its messiness and physicality, but to make it safe, and palatable."
• Detective Arbogast asking Norman if he had spent the night with Marion was cut, however Rockett states, "Here the Censor was more alert to the ordinariness, if crudity, of the query and the audience's desire, rather than Norman's (perverted) sexuality."
• In the scene where "Norma" kills Arbogast, O'Hara demanded that the number of stabs be reduced, saying, "Drastically curtail the repeated stabbing. One stab is surely enough."
• When Chambers tells Sam and Lila, "Norman found them dead together in bed," the words "in bed" were cut.
• Shots of Norma's corpse on the ground after it had fallen over were trimmed.

Psycho was cut 1 minute and 11 seconds by Norwegian censors before its cinema release in 1960, in 1975 the movie was released uncut for the first time after 15 years.

Hitchcock hesitated in editing a superimposition of Norman and Mother's skull in the closing shot. Eventually only some copies featured the trick by then.