Monsieur Fauchery, the drama critic, takes his cousin la Faloise to the theater for the opening of a new musical featuring an exciting new star known simply as Nana. At the theater, the two men recognize many people from the fashionable world, among them, the pious Count Muffat de Beuville and his wife, Countess Sabine. When Nana appears onstage, it is obvious that she has no talent, but she possesses one outstanding quality — she is the epitome of sexuality.
At first the audience laughs until a young boy, Georges Hugon, cries out, "She's wonderful." From then until the end of the play, Nana is in control of the audience, especially during the final act when she appears on the stage virtually naked.
The next day, while Nana is making arrangements to receive her lovers, fans who had seen her the preceding evening begin to call upon her. Among the visitors are Count Muffat and his father-in-law, the Marquis de Chouard, who pretends to come to collect money for a charitable organization. Both men are visibly affected by the presence of Nana. A wealthy banker named Steiner also comes, and even though he has a reputation for spending fortunes on actresses, Nana refuses to see him.
The following week, at a party given by the Count Muffat, the discussion between the men concerns a party that Nana is giving after her performance. She has told Fauchery to invite the count to the party, but most of the men think that he will not accept. At the party, more people come than Nana had expected; but the count does not come. At the end of the party, Nana decides it is time to look after her own interest and lets Steiner know that she will accept him as a lover.
As Nana's reputation spreads, soon foreign dignitaries begin to come to the theater to see her. Count Muffat must accompany an English prince to the theater and while there can hardly constrain himself because Nana has aroused in him unknown desires. Before the prince takes her away for the evening, the count discovers that Steiner has bought her a country house close to a family he often visits. She tells him to come see her there.
The country house is owned by Madame Hugon, the mother of Georges, who shouted in the theater that Nana was wonderful. When Georges hears about Nana's visit, he goes to see her. He is so young that Nana does not want to accept him as a lover, but after some mild persuasion she succumbs. This new relationship pleases her so much that she decides to postpone her affair with Count Muffat. After a week, however, Georges' relationship is discovered and his mother forces him to remain at home. Then Count Muffat slips into Nana's bedroom and begins his love affair with her.
Three months later, Nana begins to resent the fact that Count Muffat never gives her much money. Furthermore, she has formed an infatuation for an actor named Fontan. When both Muffat and Steiner arrive and find her in bed with Fontan, Nana throws both her old lovers out and decides to be true to Fontan. However, the actor soon tires of Nana and begins beating her brutally. Finally, he even locks her out of her apartment.
Nana now decides to renew her relationship with Count Muffat but makes it clear to him that she expects much more than she previously received. The count agrees to all her demands, buys her an expensive mansion, furnishes it elegantly, and gives her twelve thousand francs a month for expenses. Still Nana is not satisfied; she begins to have relations with other men, even men whom she picks up from the streets. Out of boredom, she begins to experiment with lesbian love and finds that it is rather pleasant. Count Muffat must learn to accept all of her vagaries or else leave. By now he is so completely enslaved that he cannot deny her anything.
At the famous race, the Prix de Paris, one of the horses is named after Nana. Everyone comes to the race and many bet on the filly, Nana. After the race, which is won by Nana, the owner of the stable, Count Vandeuvres, is suspected of some shady transactions and commits suicide by setting fire to himself and his stables. Nana, however, is celebrated because her namesake won the race.
No amount of money or pleasure seems to satisfy Nana. She begins to spend money so wildly that she has to have many more lovers to supply her insatiable demands. Quickly, she begins to go through the fortunes of many men and leaves them destitute and bankrupt. Through all of her experiences, the count remains imprisoned by her capricious behavior. Only when he unexpectedly discovers her in bed with his decrepit father-in-law is he shocked back into his senses. But by then, he too is a broken man.
One day, Nana disappears from Paris. No one knows of her whereabouts, but rumors begin to grow up about her. All of the rumors concern huge sums of money and fantastic lovers for Nana. One day, it is discovered that Nana is in a hotel in Paris dying of smallpox. Many of the old actresses and courtesans go there to see her, but they are too late. Now, only Nana's body, corrupted by the ravages of the disease, lies unclaimed in the austere hotel room.