Rodolfo, a poet, and Marcello, a painter, huddle around a dwindling fire in their attic apartment. Rodolfo decides to burn his latest play in order to keep warm. Their two roommates enter: Colline, a philosopher, and Schaunard, a musician, who brings a bounty of wood, food and wine for the group. The four friends prepare to celebrate Christmas Eve at a nearby café, but just as they are about to leave, their landlord, Benoit, enters and demands their delinquent rent. He is quickly overwhelmed with wine and good cheer and leaves empty-handed, after which the artists head to the Café Momus. Rodolfo stays behind to work. Mimì, a neighbor, arrives and asks him to relight her candle but faints once she enters the apartment. After she revives, Rodolfo invents excuses to keep her there, finally declaring his love for her. Mimì responds that she loves him too and they leave together for the Café Momus.

At the Café Momus, Rodolfo introduces Mimì to his friends, who welcome her with bohemian bonhomie. Meanwhile, Marcello’s old flame Musetta has arrived at the café in the company of her new admirer Alcindoro, a rich old civil servant. Musetta, however, is tired of Alcindoro and sends him off on an errand so that she can reunite with Marcello. The friends head off together into the night, leaving Alcindoro to pay their bill.

Outside an inn near the gates of Paris, Mimì searches for Marcello, who is now living there with Musetta. Rodolfo has abandoned her in a fit of jealousy and Mimì seeks Marcello’s advice. Seeing that Mimì is very ill, Marcello tells her that he thinks it is best that she and Rodolfo part. As Rodolfo enters, Mimì conceals herself. Rodolfo confesses to Marcello that he left Mimì because he is afraid that she is dying. If she leaves him, she could find a wealthy suitor to make her final days more comfortable. Realizing that he has been overheard, Rodolfo rushes to Mimì. Simultaneously, Marcello rages at Musetta about her flirtatious behavior. As Mimì and Rodolfo reconcile, Musetta and Marcello separate.

Several months later, back in their attic apartment, Marcello and Rodolfo try to forget Musetta and Mimì, who have both left them for wealthier men. Schaunard and Colline enter with a modest supper and the four men do their best to cheer each other up. Suddenly, Musetta arrives with Mimì, whom she had found ill in the street. The friends go out to fetch help, leaving Mimì and Rodolfo alone together. Shortly after the friends return, Mimì appears to be resting comfortably but the gravity of her illness soon becomes evident and Rodolfo is forced to face grim reality.