The scene is set in and around Paris in the 1840s.

Despite persistent illness, the courtesan Violetta Valery entertains as usual, insisting that she can only live a life dedicated to pleasure. She is introduced to Alfredo, a young man from the provinces with whom she flirts. Alfredo finds her at a moment when she cannot disguise her illness. Violetta is touched by his concern for her as Alfredo declares his love. Violetta offers friendship and tells him to call on her again when the camelia she gives him has faded. Alfredo leaves, and Violetta is torn between a desire for the romance he offers and her life of pleasure.

Violetta and Alfredo are now living happily in the country. However, Alfredo learns from Annina, Violetta’s maid, that she has been secretly selling her jewels to support them. Alfredo rushes to Paris to borrow money so that he can reimburse Violetta. The elder Germont arrives and begs Violetta to break off the liaison because the scandal threatens his daughter’s forthcoming marriage. Reluctantly, Violetta agrees to make the sacrifice demanded of her. When Alfredo returns, Violetta assures him of her love, but then departs, leaving him a note in which she claims she is returning to a former client in Paris. The elder Germont returns to console Alfredo, but Alfredo leaves to find Violetta and seek revenge.

Alfredo and Violetta meet at a gambling party given by another courtesan, Flora. Alfredo antagonizes the Baron for whom he believes Violetta has left him. Violetta begs Alfredo to leave the party, but instead he makes a scene, publicly denouncing and humiliating Violetta. Furiously he casts all his winnings from the gambling table at her feet. She faints in the arms of Flora and Grenvil. Alfredo’s father arrives and reprimands Alfredo for insulting Violetta while the Baron challenges him to a duel.

Violetta now lies dying. She rereads a letter from Germont saying that he has told his son of her sacrifice and that Alfredo will return to beg her forgiveness. When Alfredo arrives, they are joyously reunited and plan to leave Paris so she may recover her health. She tries to dress, but collapses. Violetta recounts the happiness they have experienced and the joy she feels once again, as she dies in Alfredo’s arms.