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: An art lover, Bertolucci drew inspiration from the works of the Irish-born British artist Francis Bacon for the opening sequence of cast and crew credits. According to Andy Warhol, the film was based on Warhol's own Blue Movie film released a few years earlier in 1969.
- 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.
- Fanservice: Schneider gets naked. A lot. Brando, however, doesn't — he did in the original cut, but Bernardo removed the scene. Sorry, ladies.
- 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.
- 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.
- Politically Incorrect Hero: Paul inherited some underlying baggage from his dead wife.
- 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.