The exteriors of the museum scene were shot in New York. The interiors however, were shot in the Philadelphia Museum of Art (note the griffin logo on the map Angie Dickinson checks, it's their logo). The large gorilla painting that she views (called 'Reclining Nude') now resides in the office of the wholesale and retail operations manager of the museum.
In the Angie Dickinson shower scene, a body double is used. When the film first came out the producers encouraged the then 48 year old Dickinson to claim the body was hers. However, it soon came out that it was actually Victoria Johnson (although initially it was suggested that it was de Palma's wife Nancy Allen).
In 1982, Dressed to Kill had its television broadcast premier on NBC. During this broadcast, the following dialog slipped past the censors and was aired to millions: Dr. Elliot: "When was the last time you had sexual intercourse with your wife, Lieutenant?" Detective Marino: "Now what the fuck is it to you?"
Angie Dickinson said the scene where her character gets seduced in the back of a cab was filmed on location in New York, where several gawkers observed the scene and shouted, "Right on, Police Woman!" (referring to her previous TV role).
In the late 1970s, Brian De Palma wrote a screenplay based on Gerald Walker's article "Cruising", but was unable to obtain the rights to the material. Cruising, the story of a series of brutal murders in the gay New York underworld, was subsequently adapted and directed by William Friedkin, while De Palma fashioned some of the elements from his own Cruising screenplay into Dressed to Kill. Both films were released, to great controversy (and after numerous battles with the MPAA to avoid X ratings), in 1980.
Sean Connery was offered the role of Robert Elliott by Brian De Palma, and was enthusiastic about it, but declined on account of previously acquired commitments. They would later work together on The Untouchables, which Connery would win the Academy Award for.
Victoria Johnson volunteered to not take a credit as Angie Dickinson's body double for the shower scene. Moreover, since Johnson is a redhead she had to dye her pubic hair blonde so she could effectively double for Dickinson in the shower scene.
Slammed at the time for being misogynistic, with it's portrait of a frustrated housewife getting stalked and brutally murdered, NOW organized a huge protest of this movie back in 1980, which of course only boosted ticket sales.
The movie originally started with the killer (disguised through lighting and clever photography) performing his own ad hoc sex change operation in the bathroom. This was changed to Angie Dickenson fantasizing in the shower.
It took poster photographic art director Stephen Sayadian five days to find the stiletto high heel shoes that were used in the one-sheet theatrical poster. Moreover, since said shoes were size eleven they had to be stuffed with tissue paper in order for the model to wear them.
This can be seen as an inversion of the Psycho formula. In Psycho an introverted young man and his mother are the villians. The psychiatrist is the good guy who comes in at the end to solve the crime and explain Norman's devious serial killing/cross dressing ways to everybody. In Dressed to Kill the psychiatrist is the bad guy who's a devious serial killer and cross dresser. The introverted young man and his mother are the good guys in this version.