In the cold winter of 1830, a tight-knit group of bohemians scrapes by in the Latin Quarter of Paris, chasing fame and a better life. Playwright Rodolphe, John Gilbert, and his painter roommate Marcel, Gino Corrado, struggle to pay the monthly rent demanded by their landlord Bernard, Eugene Pouyet, who threatens eviction that very night. Rodolphe reluctantly begins drafting an overdue article for a journal editor to earn money, but the editor, Agostino Borgato, rejects his work. With the help of their friends, the musician Schaunard, George Hassell, and the bookish Colline, they manage to raise the money.
Their next-door neighbor Mimi, Lillian Gish, an orphaned, friendless embroiderer, has the same problem. Bernard is attracted to her, but when she rebuffs his overtures, he issues the same eviction threat. She takes her meager belongings to the municipal pawnshop, but does not receive enough money to pay the rent. On her way back, she is nearly run over (deliberately) by the carriage of the rich, idle aristocrat Vicomte Paul. She has to fend off his advances.
When Marcel is invited to dinner by his girlfriend and downstairs neighbor, Musette, Renée Adorée, he persuades her to allow Schaunard to join them. Then the musician gets her to include Colline, who asks for Rodolphe. Seeing how cold she is, he invites her to warm herself in his apartment. Later, after she vacates her room, Rodolphe entices her to share in the food Musette has provided. Then Vicomte Paul comes over. She thinks he wants some embroidery done, not realizing he has baser motives. Rodolphe sees them together and, in a rage, accuses Mimi of having an affair. She tries to explain, but he refuses to listen.
Rodolphe tries to forget Mimi. When he runs into the editor, he is surprised to hear he was fired five weeks ago. Meanwhile, Mimi, with Musette's help, dresses up and goes with Vicomte Paul to the theatre, hoping to get Rodolphe's play accepted. She once again rejects the vicomte's advances. Returning home, she is confronted by Rodolphe. She admits having worked in secret for him. He initially forgives her, until he finds out that she went out with Vicomte Paul and jumps to the conclusion she got the money from him. He hits her, but soon apologizes when he discovers she is very sick.
Rodolphe goes to find a doctor, but she leaves before they return, explaining in a letter that she will come back when his play is a success. He searches for her for months. Out of his anguish, a new and greater play is born. This turns out to be a hit, but he is miserable without Mimi. Meanwhile, Mimi is toiling in the slums of Paris, but the hard work is too much for the frail woman. She collapses. The doctor tells her coworkers she will not live out the night. She stumbles out into the street and eventually reaches her old apartment. Rodolphe is ecstatic to see her. Their friends, however, realize her condition. While he goes to fetch her pet bird, she tells Musette she is happy, before dying.
