Psycho is a prime example of the type of film that appeared in the United States during the 1960s after the erosion of the Production Code. It was unprecedented in its depiction of sexuality and violence, right from the opening scene in which Sam and Marion are shown as lovers sharing the same bed, with Marion in a bra. In the Production Code standards of that time, unmarried couples shown in the same bed would be taboo.
According to the book Alfred Hitchcock and the Making of Psycho, the censors in charge of enforcing the Production Code wrangled with Hitchcock because some of them insisted they could see one of Leigh's breasts. Hitchcock held onto the print for several days, left it untouched, and resubmitted it for approval. Each of the censors reversed their positions: those who had previously seen the breast now did not, and those who had not, now did. They passed the film after the director removed one shot that showed the buttocks of Leigh's stand-in. The board was also upset by the racy opening, so Hitchcock said that if they let him keep the shower scene he would re-shoot the opening with them on the set. Since they did not show up for the re-shoot, the opening stayed.
Another cause of concern for the censors was that Marion was shown flushing a toilet, with its contents (torn-up note paper) fully visible. No flushing toilet had appeared in mainstream film and television in the United States at that time.
Internationally, Hitchcock was forced to make minor changes to the film, mostly to the shower scene. In Britain, the BBFC requested cuts to stabbing sounds and visible nude shots, and in New Zealand the shot of Norman washing blood from his hands was objected to. In Singapore, though the shower scene was left untouched, the murder of Arbogast, and a shot of Norman's mother's corpse were removed.
The most controversial move was Hitchcock's "no late admission" policy for the film, which was unusual for the time. It was not entirely original as Clouzot had done the same in France for Diabolique. Hitchcock thought that if people entered the theater late and never saw the star actress Janet Leigh, they would feel cheated. At first theater owners opposed the idea, claiming that they would lose business. However, after the first day, the owners enjoyed long lines of people waiting to see the film.