ACT 1
Argan believes he is afflicted with a variety of diseases and illnesses. In order to procure constant medical attention, he decides he is going to marry his daughter Angelique to his doctor’s nephew — who is also a doctor! However, Angelique has already fallen madly in love with a young man, Cleante, and when she hears the news of her father’s marriage proposal she is devastated. Argan’s wife, Beline, having only married Argan for his money, is angered at the prospect of having to pay a dowry and plots with her notary lover to scam Argan into willing his entire estate to her. But the quick-witted maid Toinette has always been suspicious of Beline’s intentions. Accordingly, when Cleante tumbles through the window she helps disguise him as a music teacher. The lovers face their situation in despair as Argan rejoices in his plan to secure his medical future.
ACT 2
Argan’s doctor, Purgeon, brings his nephew, the awkward, chicken-like Claude De Aria, to meet Angelique. Supposedly for the entertainment of the guests, Cleante and Angelique improvise an “opera”, using the opportunity to declare their love to each other. Purgeon has Claude show off his proficiency at doctoring by performing a diagnosis on Argan, during which Beline provokes Claude by telling him Angelique will never marry him. The guests leave in a huff. Toinette comes up with a plan to stop Angelique’s marriage and whatever Beline is planning. She sends Angelique to bed with a migraine and calls for “another” doctor, while Beline dances around with Argan, proclaiming him well enough not to receive any more enemas, infuriating the apothecary, Monsieur Bonnefoi. Purgeon learns of the different doctor attending to Argan and leaves him to his inevitable death. Argan demands to see the “new doctor” (Toinette in disguise) who pretends to cure him by recommending dismemberment, shaking Argan’s faith in the medical world. However, Argan still believes that only Beline cares about him, so Toinette convinces him to lie down on the floor, pretending to be dead. When Beline learns of his “death,” she dances for joy, revealing her nature to Argan. He plays dead again, and when Angelique discovers him she is heartbroken, to the point of not wanting to marry Cleante out of sorrow for her father. Realizing his follies, Argan wakes up and reconciles with his daughter, granting her permission to marry Cleante, on one condition: that he become a doctor. Toinette suggests that Argan become a doctor himself, and he takes to the idea and is initiated into the medical world.