It is Christmas Eve in Paris. In their bohemian garret apartment, Marcello is painting while Rodolfo writes. They have no firewood, so Rodolfo burns his manuscript for some heat. Colline arrives with Schaunard, who is laden with a windfall in fuel and food. When their landlord Benoit shows up to demand the rent, the bohemians prompt him to tell stories of his youth, then feign indignation at his scandalous past and throw him out.

Rodolfo’s roommates leave him behind to finish an article while they celebrate the holiday downstairs at the Café Momus. He is interrupted in his lonely work by a neighbor, Mimì, on her way upstairs; her candle has gone out and she requests a light. Overtaken by coughing as she is about to leave, she discovers that she has dropped her key. Rodolfo searches for it with her, momentarily brushing against her icy hand and offering to warm it with his own. As they exchange life stories – his as a poet, hers embroidering clothes ­ they are already falling in love.

Mimì and Rodolfo have joined his friends at the Café Momus and a holiday spirit prevails as the flirtatious coquette Musetta arrives on the arm of the doddering but wealthy Alcindoro. Musetta alternately loves and quarrels with Marcello; seeing him with his roommates and Mimì, she sets a commedia in motion by pretending that her shoe is too tight and sending Alcindoro off to buy another pair. Musetta and Marcello embrace and everyone orders expensive suppers. When Alcindoro returns, they run off, leaving him to pay the bill.

A cold dawn is breaking over a Parisian customs­house as Mimì appears, coughing and weak. A message from her brings Marcello out of a nearby tavern; Rodolfo and Musetta are inside, but Mimì refuses to join them. She tells Marcello of Rodolfo’s jealousy and says they must part; then, as she overhears Rodolfo confessing his fears for her health, her sobbing betrays her. The two lovers ruefully remember happier times and agree they must separate “without rancor.” But as Marcello discovers Musetta flirting in the tavern, he quarrels violently with her while Rodolfo and Mimì reconcile, resolving to stay together until spring arrives.

Months have passed and Marcello and Rodolfo are alone in their garret apartment, longing for their lost loves. When Schaunard and Colline arrive, the four friends attempt to forget their sorrows through some horseplay. But their revelry is interrupted by Musetta, who arrives with the news that Mimì is dying. As a last request, Mimì has asked to return to the attic where she met Rodolfo. He helps the fragile girl inside; Musetta gives her earrings to Marcello to buy medicine for Mimì, then goes to buy a muff for her hands. Colline goes to pawn his overcoat for food. Mimì and Rodolfo revive their love, then Rodolfo steps away to let her sleep. Quiet settles over the room, and at length Mimì stops breathing. As the others return and realize she has died, Rodolfo reads the news in their faces.