Don Pasquale is annoyed with his nephew Ernesto: he regards him as a good for nothing and wants to find him a wealthy marriage. However, Ernesto refuses to go along with his wishes, having fallen in love with Norina, the muse of a new group of artists. As a result Pasquale decides to disinherit his nephew and to get married himself. Impatiently he waits for his friend and adviser Doctor Malatesta who is charged with finding a suitable bride. He recommends his sister, whom Pasquale wishes to meet immediately. He reveals his wedding plans to a surprised Ernesto and throws him out of the house. Malatesta is keen to help the young couple Ernesto and Norina and plans to claim that Norina is his sister Sofronia. She should then enter a fake marriage to Pasquale and make his life hell. Norina agrees and practices an exaggeratedly innocent manner.
Ernesto is deeply unhappy. He feels homeless and betrayed by his best friend Malatesta. Pasquale on the other hand is delighted with his future wife. As Malatesta also has a lawyer ready and waiting, the marriage can be completed immediately. Ernesto arrives unexpectedly and is forced to act as a witness. No sooner is the wedding contract signed than Norina reveals herself to be domineering and possessive.
Norina uses her husband’s money to indulge her expensive taste for modern art. Pasquale is not prepared to tolerate her moods and wastefulness any longer but her mockery and lack of respect drive him to desperation. Pasquale is considering
divorce when he finds a note which reveals a secret rendezvous between his wife and a lover. This is an encounter engineered by Malatesta. Ernesto will play the lover, but making sure that Pasquale does not recognize him. Pasquale asks Malatesta to witness the adultery. Malatesta advises him to avoid a scandal. Instead he should allow Ernesto to marry Norina and to return how. His domineering wife will not tolerate any rival and soon drive them away. Pasquale is forced to give his consent and to see that he has been tricked. He forgives the others and discovers a life of happiness.