Paul (Brando), a 45-year old American who lives and owns a hotel abroad in Paris, is mourning the suicide of his wife when he meets Parisian woman Jeanne (Schneider) whilst apartment hunting. Jeanne herself is engaged to a film director, though Paul does not know this initially. The two feel lonely and marginalized, so they begin a torrid affair, of which the rules, as set by Paul, are that they do not tell each other any personal details about themselves; not even their names. As time goes by, Paul becomes possessive and starts to act abusively towards Jeanne; in one infamous scene he anally rapes her using butter as lubricant. Things go downhill from there.
When released, the film's groundbreaking subject matter caused a media frenzy and Moral Guardian outrage, despite some glowing critical reception and Academy Award nominations for Brando and Bertolucci. It is regarded nowadays as one of the best European films and best arthouse films ever made. It could be considered the progenitor of the Euroshlock genre. It is an obvious influence on the films of Catherine Breillat (who herself has a small appearance in the film), specifically Romance and Anatomy of Hell, both of which would help to revive the Euroshlock genre in the 2000s.
This film provides examples of:
- All Girls Want Bad Boys: Invoked and deconstructed — Paul starts out seeming Troubled, but Cute but gets increasingly nasty and abusive towards Jeanne, both physically and verbally... yet even after some of his nastier moments she confesses to having fallen in love with him. Jeanne is, however, portrayed as rather messed up, and it gets increasingly obvious just how toxic their relationship is.
- Art Imitates Art: The film's opening credits include two paintings by Francis Bacon: Double Portrait of Lucian Freud and Frank Auerbach and Study for a Portrait of Isabel Rawsthorne. The hues used in the film were inspired by the paintings of Bacon. During pre-production, Bertolucci frequently visited an exhibit of Bacon's paintings at the Grand Palais in Paris; he said that the light and colour in Bacon's paintings reminded him of Paris in the winter, when "the lights of the stores are on, and there is a very beautiful contrast between the leaden gray of the wintry sky and the warmth of the show windows...the light in the paintings was the major source of inspiration for the style we were looking for".
- Bacon's painting style often depicted human skin like raw meat and the painter's inspiration included meat hanging in a butcher shops window and human skin diseases.
- Cinematographer Vittorio Storaro had previously worked with Bertolucci on The Conformist and often used an azure hue in the film. Storaro later told a reporter that "after The Conformist I had a moment of crisis; I was asking myself: what can come after azure?...I did not have the slightest idea that an orange film could be born. We needed another kind of emotion...It was the case of Last Tango.
- Bertolucci and Storaro took inspiration from Bacon's paintings by using "rich oranges, light and cool grays, icy whites, and occasional reds combine[d] with Bertolucci's own tasteful choices of soft browns, blond browns, and delicate whites with bluish and pink shadings".
- Bertolucci took Marlon Brando to the Bacon exhibit and told Brando that he "wanted him to compare himself with Bacon's human figures because I felt that, like them, Marlon's face and body were characterized by a strange and infernal plasticity. I wanted Paul to be like the figures that obsessively return in Bacon: faces eaten by something coming from the inside".
- Bastard Boyfriend: Both Jeanne's movie director boyfriend and Paul, each in their way; the movie director is less openly a bastard but cares more about his art and artistic vision than he does about Jeanne, and Paul becomes directly abusive — especially after their relationship gets beyond anonymous sex.
- Clingy Jealous Girl: Inverted at the end when Paul becomes the Spear Counterpart and effectively a Stalker with a Crush.
- Dark and Troubled Past: Paul's emotional baggage over his wife's suicide and arguably Jeanne's childhood.
- Downer Ending: The film ends with Jeanne killing Paul after she revealed her name to him, leading her into a B.S.O.D..
- Dysfunction Junction: Neither the two main characters or anyone in the film for that matter, could be called "well-balanced". This works its way into the tragedy of the movie, as each character's issues ensure they'll either spend life together in a harmful cycle or break out of it and find other dysfunctional people.
- Heroic BSoD: Jeanne suffers one at the very end of the film, after she has shot and killed Paul.
- Instant Seduction: Or possibly rape...it's a little vague. Within a few minutes of their first meeting, Paul grabs Jeanne and proceeds to have sex with her against a wall. It's ambiguous just how consensual it is on her part.
- Killing in Self-Defense: At the end, Jeanne shoots Paul dead defending herself from him.
- Love Martyr: Jeanne to start, then Paul when he decides to pursue an actual emotional relationship with her at the end, eventually literally embodying this trope.
- Love Triangle: A particularly dark one of Type 7 in Triang Relations: Jeanne is in a relationship with the film director, but she's also in a relationship with Paul. Neither of them knows about the other's involvement at all, though much of the drama comes more from Paul's (and to an extent Jeanne's) emotional issues.
- Ms. Fanservice: Jeanne is young and pretty. She gets naked in many sex scenes. Brando, however, doesn't — he did in the original cut, but Bernardo removed the scene. Sorry, ladies.
- Politically Incorrect Hero: Paul inherited some underlying baggage from his dead wife.
- Rape as Drama: Paul explicitly anally rapes Jeanne as their relationship deteriorates. In other cases, he may have too, as the consensualness of many sexual encounters is left dubious.
- Right Through His Pants: Twice Paul seduces/rapes Jeanne without taking his pants off, including in the infamous "butter" scene.
- Romantic False Lead: Jeanne's movie director boyfriend/fiance who's so thoroughly absorbed in his work that he treats her as much as scenery as a Love Interest. Played by Jean-Pierre Léaud himself.
- Wall Bang Her: The first sex scene between Paul and Jeanne, done within minutes of them first meeting one another. It's left ambiguous whether this is Instant Seduction or straight-up rape.