Part One Alfredo Germont arrives at a party at the home of Violetta Valéry, a renowned courtesan. She is surprised to learn of his devotion to her, and of his concern during her recent illness. Alfredo leads a toast to love; Violetta responds with a toast to pleasure and excitement. Feeling faint, she excuses herself to rest. Alfredo follows and begs her to allow him to love and care for her. She tells him she is not interested in such heroic commitment, but invites him to return the next day. Alone, she wonders if she is capable of experiencing love. Dismissing the idea as nonsense, she determines to live for freedom and pleasure alone.
Violetta flees her extravagant life in Paris to be with Alfredo. After learning that she plans to sell her belongings to maintain their country retreat, Alfredo goes to Paris to pay their debts. While he is away, Giorgio Germont visits Violetta. He tells her that Alfredo, his son, intends to give her all his possessions. She tells the elder Germont that she would never accept and reveals that she is making sacrifices to maintain their life together. Although impressed by her nobility, Germont begs her to leave his son, as her association with the family will ruin his daughter’s future prospects. Violetta finally agrees, asking only that, after her death, Germont tell his daughter the truth. Later, when Alfredo receives a letter from Violetta, claiming she no longer loves him, he is devastated.
Part Two Violetta attends a party with her new protector, Baron Douphol. The men gamble, and Alfredo is the winner. Violetta pulls Alfredo aside and begs him to leave; he refuses and threatens to duel with the Baron. Unable to break her promise to the elder Germont, Violetta insists that she loves the Baron. Furious and hurt, Alfredo calls the guests together and publicly insults Violetta.
Now on her deathbed and tended by Annina, Violetta re-reads a letter from Giorgio Germont. According to the letter, Alfredo went abroad after dueling with the Baron; his father wrote to him there, explaining Violetta’s sacrifice. Alfredo arrives, asking forgiveness and pledging eternal love. Violetta expresses hope for their future together, but she is very weak. Alfredo sends Annina for the Doctor. He arrives with Giorgio Germont, who reproaches himself for his earlier behavior toward Violetta. He asks forgiveness and pledges to accept her as a daughter, but he is too late.