It is a cold night in the garret shared by Rodolfo, a poet, Marcello, a painter, Colline, a philosopher, and Schaunard, a musician. Marcello is at work on a painting, and Rodolfo is trying to write. He suggests that he sacrifice his tragedy for fuel, and into the stove goes the manuscript. Colline enters, closely followed by Schaunard, who has managed a windfall – he is laden with fuel and food. Benoit, their landlord, wants his rent. The quartet invites him in, and then feign horror as the old man boasts of his conquests. Mock-indignant, they eject him.

As the others go off to the Cafe Momus, Rodolfo stays behind to try to write. A timid knock interrupts him, and he discovers on the threshold a frail young woman. It is Mimi and she asks a light for her candle, which Rodolfo supplies. But a breeze blows out both candles, and in her confusion, Mimi drops her key. As they search in the darkness, he touches her hand. Tenderly, Rodolfo offers to warm her cold hands with his own. He tells her of his life as a poet, and she describes her work. The others call from the street, and as they go off to the Cafe Momus, Rodolfo confesses that he has fallen in love.

A happy crowd swirls about the Café Momus. The dashing Musetta who alternately loves and quarrels with Marcello, enters on the arm of the doddering Alcindoro. When she sees Mimi and the four young men, Musetta pretends that her shoe is pinching, and sends Alcindoro off to have it fixed, whereupon she joins Marcello. They order an expensive supper. As Alcindoro enters from the cobbler’s shop, the others run off, leaving him to pay the bills.

Months later, at the gate of the city, Mimi comes to the inn besides the gate. A cough racks her, and she is very weak. A message brings Marcello out of the tavern. Rodolfo and Musetta are with him, but Mimi refuses to join them. She tells Marcello of Rodolfo’s jealousy, and says they must part. Just then Rodolfo comes out to look for Marcello. Mimi hides but her cough gives her away. Regretfully, the two lovers remember happier times, but agree that they must see each other no more. In the meantime, Marcello has discovered Musetta flirting with one of the men in the tavern. Their violent quarrel breaks through the tender phrases of Mimi and Rodolfo’s farewell.

Back in their garret, Marcello and Rodolfo long for their lost loves. Surreptitiously, Rodolfo fingers the little bonnet he bought Mimi. But Schaunard and Colline come in, both in high good humor, and a frolic ensues. Just as the fun is at its height, Musetta runs in with the dreadful news that Mimi is outside, and the poor girl is dying. Rodolfo helps the fast-sinking girl to the cot, and gently supports her.

There is nothing in the place to help Mimi. Musetta gives her earrings to Marcello, asking him to buy medicine for the dying girl, while Colline goes off to pawn his overcoat to buy food. Musetta leaves to find a muff for Mimi’s poor, cold hands. Left alone, the lovers recall incidents from happier days. The others return, and are aware before Rodolfo that Mimi is gone. He turns and reads the news in their faces. With a cry he falls on Mimi’s lifeless body.