Among the smoking chimneys of 1830 Paris in their cheerless garret in the Latin Quarter, the near-destitute artist Marcello and poet Rodolfo try to keep warm on Christmas Eve by feeding the stove with pages from Rodolfo’s drama. Before long they are joined by their roommates: Colline, a young philosopher, and Schaunard, a musician, who brings with him food, fuel and funds. As the four Bohemians celebrate their sudden good fortune, Benoit, the landlord, interrupts their gaiety with a bill for the rent. Plying the older man with wine, they encourage him to tell of his flirtations, then throw him out in pretended indignation. As his friends depart for further merrymaking, Rodolfo promises to join them later at the Café Momus. Alone and beginning to write, he is surprised by a knock at the door; this time the visitor turns out to be a pretty young neighbor, Mimi, whose candle has gone out on the drafty stairway. No sooner does the girl enter than she feels faint; after giving her a sip of wine to revive her, Rodolfo helps her to the door, relighting her candle. Suddenly Mimi realizes that she has lost her key; as the two search for it, their candles are blown out. In the moonlight the poet takes the girl’s shivering hand to warm, telling her of his dreams. She responds by telling him how she lives alone in her lofty attic, embroidering flowers and waiting for the first kiss of April’s sun. When Rodolfo’s friends are heard from the distance, urging him to join them, he calls back that he will come along shortly and bring a friend. Expressing their new-found rapture, Mimi and Rodolfo embrace and leave for the café arm in arm.

Amid the shouts of hawkers selling their wares, Rodolfo buys Mimi a bonnet at a shop near the Café Momus. The toy-vendor Parpignol passes by, besieged by a group of eager children. After the poet introduces Mimi to his friends, they all select a table and order their meal. Soon Musetta, Marcello’s high-spirited former sweetheart, makes a noisy entrance on the arm of her rich new admirer, the elderly Alcindoro; the ensuing tumult reaches its height when Musetta, trying to regain the painter’s attention, sings a waltz about how popular she is wherever she goes. To get rid of Alcindoro, she complains that her shoe pinches, sending the old man off to fetch a new pair. The moment he is gone she falls into Marcello’s open arms, and when the waiter comes with the bill, she tells him to charge everything to Alcindoro. A detachment of soldiers marches by the café and the Bohemians fall in behind, leaving Alcindoro, who rushes back with Musetta’s new shoes, to face the bill.

On the outskirts of Paris on a snowy morning, a customs officer admits farm women to the city with their butter and cheese. Late merrymakers can still be heard within a tavern, clinking their beer glasses. Soon Mimi wanders in, searching for the place where Marcello now lives with Musetta. When Marcello emerges, Mimi confesses to him that she is distraught over Rodolfo’s incessant jealousy: it would be best for them to part. Rodolfo, who has been asleep in the tavern, is heard from within and Mimi quickly hides. The poet tells Marcello that he wants to separate from Mimi because she is so fickle, but, pressed for the real reason, he breaks down, saying that her illness can only grow worse in the poverty they live in. Overcome with tears, Mimi stumbles forth from her hiding place to bid her lover farewell, just as Marcello runs back into the tavern at a shriek of laughter from Musetta. While Mimi and Rodolfo exchange memories of their happiness, Musetta dashes from the tavern quarreling with Marcello, who has caught her flirting. The painter and his mistress part, shouting insults at one another, but Mimi and Rodolfo decide to remain together until spring.

Separated from their sweethearts, Rodolfo and Marcello lament their loneliness in the garret. Colline and Schaunard join them, bringing a meager meal; to lighten their spirits, the four friends stage a mock ball, which turns into a furious duel. At the height of the hilarity, Musetta bursts into the room to announce that Mimi is downstairs, so weak that she lacks the strength to climb the stairs. Rodolfo runs to assist her as Musetta tells how Mimi begged to be taken to Rodolfo so that she could die near him. When they have made the girl as comfortable as possible, Musetta leaves to sell her earrings to buy medicine and Colline goes off to pawn the coat that has served him so faithfully and so long. Left alone, Mimi wistfully reminds Rodolfo of their first happy days together, but she is seized by a violent fit of coughing. When the others return, Musetta gives Mimi a muff to warm her hands. As the girl peacefully drifts into death, Rodolfo lowers the blinds to soften the light. Suddenly Schaunard discovers that Mimi is dead. Rodolfo, the last to realize the fact, throws himself despairingly on her body, calling her name.