The action takes place in and around Paris in the 1840s.
ACT I
A salon in Violetta’s house. August.
Violetta Valery welcomes to her party Flora Bervoix who is accompanied by the Marquis d’Obigny. Gastone arrives with his friend, Alfredo, and tells Violetta that during her recent illness the young man came to her house every day for news about her health. Violetta chides the Baron Douphol, her current lover, for his lack of attention during that time. To the guests’ approval, Alfredo and Violetta sing a drinking song.
After announcing that it is time to dance, Violetta almost faints while trying to leave the room. Alfredo stays behind with her to profess his love, and Violetta gives him a flower and tells him to return tomorrow when it has withered. Alone, Violetta wonders if Alfredo is the one person she could truly love.
INTERMISSION
ACT II, scene 1
A country house near Paris. January.
Alfredo muses that Violetta has given up her former life and now lives quietly with him. The servant Annina returns, having been sent to Paris by Violetta to sell her mistress’ possessions in order to raise money for unpaid bills. Shocked at this news, Alfredo leaves for the city to rectify Violetta’s finances.
Violetta enters, and the servant Giuseppe gives her a party invitation from Flora. A stranger is announced and introduces himself as Alfredo’s father, Giorgio Germont. He accuses Violetta of ruining his son, but she shows him papers that prove that it is she, not Alfredo, who pays for their life together. Germont explains he is here to ask for a sacrifice: the marriage of his daughter cannot take place if Violetta and Alfredo live together. After much reluctance, Violetta agrees to abandon Alfredo.
Violetta starts to write a letter to Alfredo but is interrupted by his return. She expresses her deep love for him before exiting. While Alfredo waits for his father, a messenger arrives with a note from Violetta that states she has left him. Giorgio enters and asks his son to return home. However, Alfredo sees the invitation from Flora and runs off to her party to take his revenge.
ACT II, scene 2
A gallery in Flora’s house. That evening.
The Marquis d’Obigny tells Flora that Violetta and Alfredo have separated. Dressed as Gypsy girls and matadors, Flora’s guests entertain each other. Alfredo enters and goes to a card table. Soon Violetta arrives escorted by Baron Douphol who jealously orders her not to speak to Alfredo. The Baron and Alfredo gamble at cards, and Alfredo wins repeatedly.
Alone with Alfredo, Violetta says it was the Baron who forced her to abandon him. Alfredo calls in the guests and throws money at Violetta to repay her. Having followed his son to the party, Germont criticizes his son’s behavior. The Baron challenges Alfredo to a duel.
INTERMISSION
ACT III
Violetta’s bedroom. February.
The next month, Violetta is gravely ill. Dr. Grenvil confides to Annina that Violetta has only a few hours to leave. Alone, Violetta rereads a letter from Alfredo’s father. It states that the duel has taken place. The Baron is recovering from a wound, and Alfredo has gone abroad but will return to her.
Annina prepares Violetta for a surprise: Alfredo is there. The lovers embrace and dream of leaving Paris for a life together. Germont arrives and is remorseful for the harm he has caused Violetta. Violetta hands Alfredo a small portrait of herself and tells him to give it to the girl he marries. After feeling momentarily renewed, Violetta collapses dead.