Don Pasquale, a wealthy old bachelor, is outraged when he hears his nephew Ernesto intends to marry the impoverished widow Norina. He determines to marry himself and disinherit Ernesto. Ernesto and Norina despair, but their friend Doctor Malatesta promises to help them – and teach Pasquale a lesson. Malatesta persuades Norina to disguise herself as his sister, then presents her to Don Pasquale as a potential bride. Pasquale is so delighted with the young woman’s docile behaviour that he demands they marry at once.
The marriage takes place – witnessed by a fake notary – after which the young bride becomes utterly overbearing and unpleasant, tormenting her ‘husband’. When Pasquale discovers a note from his ‘wife’ arranging a rendezvous with a lover, he determines to confront her and end his misery. The conspirators are now set to reveal their trickery, but will Don Pasquale forgive them?