Prehistory
Count Waldner has run up so many gambling debts that, in the end, he has had to move into a hotel in Vienna, together with his wife, Adelaide, and their two daughters, Arabella and Zdenka. In order to solve his financial problems, he plans to marry Arabella to someone rich. And since they do not have the money to bring up both daughters in a manner befitting their social status, Zdenka is disguised as a young man, ‘Zdenko’.

Act One
Adelaide has asked a fortune-teller to predict her future with cards: Arabella will get a rich husband, she says, but a second daughter could endanger the match. Adelaide hopes that Arabella’s potential husband will be one of her three admirers, Count Elemer, Count Dominik or Count Lamoral. The penniless lieutenant Matteo is also in love with Arabella, while Zdenka has feelings for Matteo and writes love letters to him in Arabella’s name. Despite Arabella’s dismissive behaviour towards him, these letters only encourage him to keep visiting her. Arabella, however, is waiting for ‘the right one’ and sees a man on the street whose gaze meets her own. Count Waldner has sent a former regimental comrade a picture of Arabella in the hope that he might want to marry her. His friend’s nephew, Mandryka, receives the picture and promptly falls in love with Arabella. He visits Waldner and asks for Arabella’s hand in marriage. Waldner will introduce them to each other at the coachman’s ball.

Act Two
At the coachman’s ball, Arabella recognizes Mandryka as the man she saw on the street. After the two of them have confessed their love for each other, Arabella asks Mandryka to leave her alone, in order for her to take leave of her girlhood. Meanwhile, Zdenka gives Matteo the key to a hotel room. She tells him that Arabella will wait for him there. Mandryka overhears their conversation and feels deceived. Shortly thereafter he receives a message from Arabella, telling him that she has already returned to the hotel, and he believes his suspicions are confirmed. An altercation ensues and, at Waldner’s request, the bewildered Mandryka agrees to confront Arabella directly.

Act Three
In the foyer of the hotel, Matteo meets Arabella. He is convinced that he has just spent the night with her. Arabella denies it. But not even Waldner’s efforts can solve the matter and there is threat of a duel between Mandryka and Matteo. Then Zdenka appears, admitting to being a girl and that she pretended to be Arabella. Mandryka is ashamed. He asks Waldner to allow Matteo to wed Zdenka but is himself convinced that he has lost the love of Arabella; but then she forgives him.