Giovanni, a successful writer, and his wife Lidia visit their friend Tommaso who is dying in hospital. They leave together to attend Giovanni's book promotion. At the book promotion, Giovanni gets caught up talking to everyone at the event and Lidia sneaks out and goes on a long tour through the city of Milan. Eventually, they meet back at home and they decide to go out together to an erotic dance performance at a night club. After, they visit the party of a billionaire, who wants Giovanni to write a book about the history of his company. Both flirt with others, and they both notice this fact. Later Lidia phones the hospital and is informed, that her friend Tommaso is now dead. Tired of her husband in the morning she tells her husband that she doesn't love him anymore.
The film is a recurring joke in the films of Monty Python. In the trailer for Monty Python and the Holy Grail, it is used as an example of a run-of-the-mill film, along with Herbie Rides Again. At the end of Monty Python’s Life of Brian, a message appears at the end of the credits, telling the audience to see La Notte if they enjoyed the film. It was originally referenced on the television show Monty Python's Flying Circus, where a director with a thick Caribbean accent is arrested for impersonating Antonioni; then Eric Idle proceeds to recite Antonioni's career and methods as the credits roll.