Violetta’s house in Paris: Violetta, a courtesan under the protection of Baron Douphol, is entertaining guests in her salon, when she is introduced to a new admirer, Alfredo Germont. After Alfredo leads a spirited toast to his hostess, the guests depart. Violetta remains behind, overcome by a bout of coughing; Alfredo also stays behind and declares his love for her, which Violetta gently discourages. After the party has finally broken up, Violetta wonders if Alfredo could be her true love; in the end, however, she believes that her death must come in the ‘vortex’ of hollow pleasures that make up her life.
A country house near Paris, three months later: Violetta and Alfredo are now living together in the country. When he learns from her maid, Annina, that Violetta has sold her possessions to pay their debts, Alfredo leaves for Paris to raise the necessary money. In his absence, Violetta receives an unexpected call from his father. He begs her to break off the attachment; otherwise, his daughter’s marriage into a respectable family will be threatened. Violetta finally agrees, and when Germont leaves, writes a farewell note. When Alfredo returns and reads it, he refuses the consolation of his father and rushes off to Paris to avenge himself for what he believes to be a betrayal.
Flora’s House in Paris, the same night: A party is in progress. Alfredo appears alone, followed by Violetta escorted by Baron Douphol. The two men play cards and Alfredo wins. When she has the chance, Violetta sees Alfredo alone and begs him to avoid a duel. Alfredo summons the guests to witness the repayment of his debts and flings his winnings in her face. The Baron challenges him. Germont enters in time to witness his son’s outburst and reproaches him for it.
Violetta’s bedroom, a few months later: Dr. Grenvil tells Annina that her mistress is dying. Violetta reads a letter from Germont that says Alfredo has learned of her sacrifice and is on his way to her to ask her forgiveness. The lovers are reunited and Germont arrives to give his blessing; but it is too late and Violetta dies.