Critical response
On Rotten Tomatoes, the film holds an approval rating of 67% based on 33 reviews, with an average rating of 5.8/10. The website's critics consensus reads, "The Night Porter's salaciousness gives its exploration of historical trauma a bitter aftertaste, but audiences seeking provocation are unlikely to forget the sting of this erotic drama." In response to The Night Porter, Cavani was both celebrated for her courage in dealing with the theme of sexual transgression and, simultaneously, castigated for the controversial manner in which she presented that transgression within the context of a Nazi Holocaust narrative. The film met with particular criticism in the United States, with several high-profile American film critics finding the subject matter obscene.
Roger Ebert of the Chicago Sun-Times thought the main roles were well-performed, but nonetheless gave the film one star out of four, and called The Night Porter "as nasty as it is lubricious, a despicable attempt to titillate us by exploiting memories of persecution and suffering", while adding that he did not "object per se to the movie's subject matter." In The New York Times, Nora Sayre praised the performances of Bogarde and Rampling, and the "dark, rich tones" of the cinematography, but began her review by writing, "If you don't love pain, you won't find The Night Porter erotic—and by now, even painbuffs may be satiated with Nazi decadence." Vincent Canby, also writing for The New York Times, called it "romantic pornography" and "a piece of junk". Leonard Maltin's 2015 Movie Guide called it a "[s]leazy, bizarre drama", awarding it two out of four stars.
In Europe, the film was met with opposition as well. German magazine Filmdienst categorised the film as "political pornography". Despite the poor German critical response, it grossed over $1.3 million. In the French Cahiers du Cinéma, Michel Foucault criticised what he saw as a sexualised vision of Nazism.
In her 2000 essay for the Criterion Collection release, Annette Insdorf called The Night Porter "a provocative and problematic film. ... [I]t can be seen as an exercise in perversion and exploitation of the Holocaust for the sake of sensationalism. On the other hand, a closer reading of this English-language psychological thriller suggests a dark vision of compelling characters doomed by their World War II past." In his 2020 review for The Guardian, Peter Bradshaw described the film as a "dated" but "intriguing period piece", adding, "Perhaps there is something in its very crassness, horror and tastelessness that does at least jolt us towards an acknowledgment of pure evil."
Mikel J. Koven characterised The Night Porter as a "Nazi sexploitation" film.
