Violetta has been to a sanatorium to treat her tuberculosis. On her return to health she throws a party to mark her re-emergence in the demi-monde under the protection of Baron Duphol. Her guests have just completed a long lunch and the Baron is reading the last pages of a novel by Dumas to Violetta as Flora enters with her protector the Marquis.
Alfredo is introduced to Violetta by the decadent Gaston. Alfredo has begged Gaston to introduce him to Violetta. He has long been enthralled by her and has enquired after Violetta every day of her illness.
Violetta insists that everyone sits together and drinks a toast to the occasion. Alfredo is prevailed upon to sing a drinking song from Provence.
As the guests leave to dance in the ballroom, Violetta feels faint and is momentarily left alone. Alfredo re-enters and confesses his love for her. She asks him to return the following day.
After her guests leave and she is alone, Violetta begins to consider the conflicting feelings of love and hedonism that are pulling her in opposite directions.
Violetta and Alfredo have been living together for three months in a house in the country. When Alfredo discovers that Violetta is selling her belongings to pay for their expenses, he is conscience-stricken and leaves to visit his father, to raise some money. His father however has decided to call on Violetta to persuade her to give up Alfredo. Alfredo’s sister hopes to be married soon, and his relationship with Violetta jeopardises the family’s honour. Violetta realises that as a ‘fallen woman’ she would destroy Alfredo’s family and consents to leave him. She decides to leave instantly and writes a message to Alfredo, breaking off their affair. When Alfredo receives the message he is distraught and, despite his father’s attempts to console him, rushes off to wreak revenge on Violetta.
A party is being held in Flora’s house. Alfredo enters to join the gambling party. When Violetta enters on the arm of the Baron she freezes with tension. Alfredo begins to insult the Baron and the two rivals meet over cards, and Alfredo, unlucky in love, cannot lose a hand. The game is interrupted by dinner.
Violetta begs Alfredo to leave before Duphol seeks revenge. Alfredo insists she comes with him and, in desperation, she says she loves the Baron. Alfredo publicly humiliates Violetta and throws money at her as payment for her services. Alfredo’s father reproves him for such behaviour.
It is early morning and Violetta is sleeping. The doctor has given her only a few hours to live. Violetta rereads a letter from Alfredo’s father, telling her that the Baron was wounded in the duel with Alfredo and that Alfredo may have left the country.
But Alfredo has been told by his father of Violetta’s sacrifice and he returns — only to be confronted by the dying Violetta. He humours her by telling her that they should plan a new life away from Paris. Alfredo’s father has followed him and enters, followed by the doctor. Violetta suddenly feels revived, ready to start a new life with Alfredo — but this is only the symptoms of the last moments of her disease and she falls dead.