Paris, the 1830s. In their Latin Quarter garret, the near-destitute artist Marcello and poet Rodolfo try to keep warm on Christmas Eve by feeding the stove with pages from Rodolfo’s latest drama. They are soon joined by their roommates—Colline, a philosopher, and Schaunard, a musician, who brings food, fuel, and funds he has collected from an eccentric student. While they celebrate their unexpected fortune, the landlord, Benoit, comes to collect the rent. After making the older man drunk, they urge him to tell of his flirtations. When he does, they throw him out in mock indignation at his infidelity to his wife. As his friends depart to celebrate at the Café Momus, Rodolfo remains behind to finish an article but promises to join them later. There is another knock at the door—the visitor is Mimì, a pretty neighbor, whose candle has gone out on the stairway. As she enters the room she suddenly feels faint. Rodolfo gives her a sip of wine, then helps her to the door and relights her candle. Mimì realizes she lost her key when she fainted, and as the two search for it, both candles are blown out. Rodolfo finds the key and slips it into his pocket. In the moonlight, he takes Mimì’s hand and tells her about his dreams. She recounts her life alone in a lofty garret, embroidering flowers and waiting for the spring. Rodolfo’s friends are heard outside, calling him to join them. He responds that he is not alone and will be along shortly. Happy to have found each other, Mimì and Rodolfo leave, arm in arm, for the café.
Amid the shouts of street hawkers near the Café Momus, Rodolfo buys Mimì a bonnet and introduces her to his friends. They all sit down and order supper. The toy vendor Parpignol passes by, besieged by children. Marcello’s former sweetheart, Musetta, makes a noisy entrance on the arm of the elderly but wealthy Alcindoro. The ensuing tumult reaches its peak when, trying to gain Marcello’s attention, she loudly sings the praises of her own popularity. Sending Alcindoro off on a pretext, she finally falls into Marcello’s arms. Soldiers march by the café, and as the bohemians fall in behind, the returning Alcindoro is presented with the check.
At dawn on the snowy outskirts of Paris, a customs official admits farm women to the city. Guests are heard drinking and singing within a tavern. Mimì arrives, searching for Marcello. When the painter appears, she tells him of her distress over Rodolfo’s incessant jealousy. She says she believes it is best that they part. Rodolfo, who has been asleep in the tavern, comes outside. Mimì hides nearby, though Marcello thinks she has left. Rodolfo tells his friend that he wants to separate from Mimì, blaming her flirtatiousness. Pressed for the real reason, he breaks down, saying that her coughing can only grow worse in the poverty they share. Overcome with emotion, Mimì comes forward to say goodbye to her lover. Marcello runs back into the tavern upon hearing Musetta’s laughter. While Mimì and Rodolfo recall past happiness, Marcello returns with Musetta, quarreling about her flirting with a customer. They hurl insults at each other and part, but Mimì and Rodolfo decide to remain together until spring.
Months later in the garret, Rodolfo and Marcello, now separated from their girlfriends, reflect on their loneliness. Colline and Schaunard bring a meager meal. To lighten their spirits the four stage a dance, which turns into a mock duel. At the height of the hilarity Musetta bursts in with news that Mimì is outside, too weak to come upstairs. As Rodolfo runs to her aid, Musetta relates how Mimì begged to be taken to Rodolfo to die. She is made as comfortable as possible, while Musetta asks Marcello to sell her earrings for medicine and Colline goes off to pawn his overcoat. Left alone, Mimì and Rodolfo recall their meeting and their first happy days, but she is seized with violent coughing. When the others return, Musetta gives Mimì a muff to warm her hands and prays for her life. Mimì slowly drifts into unconsciousness. Schaunard realizes that she is dead, and Rodolfo is left desperate.