Paris, in the 1830s. A garret in the Latin Quarter, home to four friends sharing the 'bohemian' life - Rodolfo the poet, Marcello the painter, Colline the philosopher and Schaunard the musician. On Christmas Eve, Rodolfo writes his drama while Marcello works on his painting called 'The Crossing of the Red Sea'. They try to keep warm by feeding the stove with pages from Rodolfo's latest drama. They are soon joined by their roommates Colline and Schaunard, who brings food, wine, fuel, and funds he has collected from an eccentric English nobleman. While they celebrate their unexpected fortune, the landlord Benoît comes to collect the rent. After getting the older man drunk, the friends urge him to tell of his flirtations, then throw him out in mock indignation at his infidelity to his wife. As the others depart to revel at the Café Momus, Rodolfo remains behind to finish an article, promising to join them later. Then there is a timid knock at the door. It is Mimì, pale but pretty, asking for a light for her candle. He relights her candle. She immediately reappears, now in search of her lost room-key. Now both candles go out, leaving them only in moonlight from the window. They feel about the floor for the key and their hands touch. Rodolfo remarks 'how cold her little hand is', and keeps it clasped as he tells Mimì of his dreams as a poet, then asks who she might be. She introduces herself and tells that she embroiders flowers alone in a garret, longing for Spring to bring real flowers with their scent. Rodolfo's friends call from outside, telling him to join them. He responds that he is not alone and will be along shortly. Then Rodolfo ve Mimì declare their love and leave arm in arm.

The Café Momus and the square outside. Amid the shouts of street hawkers, 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 an entrance on the arm of the wealthy Alcindoro. The ensuing tumult reaches its peak when, trying to gain Marcello's attention, she loudly sings the flirtatious waltz-song. Sending Alcindoro away to buy her a new pair of shoes, Musetta finally falls into Marcello's arms. When the bill arrives for their meal, Musetta declares that Alcindoro will pay for it when he returns. Soldiers march by the café and everybody leaves in their wake except a returning Alcindoro, who is horrified at the amount of his bill.

A snowy dawn at the city boundary in February. Guests are heard drinking and singing within a tavern. Mimì arrives, searching for the place where Marcello now lives. 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. As Rodolfo emerges from the tavern, Mimì hides nearby. Rodolfo tells Marcello that he wants to separate from Mimì, blaming her flirtatiousness. Pressed for the real reason, he breaks down, saying that her illness can only grow worse in the poverty they share. Overcome with emotion, Mimì comes forward to say goodbye to her lover. Jealous-tempered 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 springtime.

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. 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 with Schaunard 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 Mimì slowly drifts into unconsciousness. Musetta prays for Mimì, but it is too late. Schaunard notices that Mimì is already dead. Seeing their faces, Rodolfo rushes to the bed and collapses in despair.