Following a debate on theatre, the Ridicules win and present 'The Love for Three Oranges'. Doctors inform the King that his son the Prince is sick with hypochondria, which can only be cured with laughter. Meanwhile, the magician Tchelio, who supports the King, and the evil witch Fata Morgana, who supports lovers Leandro and Clarice (niece of the King), play cards. Tchelio loses, and Leandro and Clarice plot to kill the Prince so that Clarice can succeed to the throne. The jester Truffaldino’s efforts to make the Prince laugh fail until he accidentally knocks Fata Morgana over. Furious, Fata Morgana curses the Prince to be obsessed by ‘love for three oranges’. At once, the Prince and Truffaldino march off to search them. Using a magic ribbon given to them by Tchelio, they distract the giant cook who guards the oranges and take them off into the surrounding desert. While the Prince sleeps, Truffaldino opens two of the oranges. Fairy princesses emerge but quickly die of thirst. The Ridicules give the Prince water to save the third princess, Ninette, and the two fall in love.  He leaves to seek clothing for Ninette so he can marry her, but, while he is gone, Fata Morgana transforms her into a giant rat and substitutes the servant Smeraldina in disguise. Tchelio and Fata Morgana meet, each accusing the other of cheating at cards, but the Ridicules intervene and capture the witch. Tchelio restores Ninette to her natural form and Fata Morgana flees with her accomplices. The opera ends with the celebration of good triumphing over evil.