When Boss Hogg and Rosco capture a Leprechaun and force him to give him not just his own pot of gold but those of his friends as well, the Grand Wizard of the Leprechauns puts him on trial. It's up to the Dukes to safe the Hogg.
Boss is babysitting his ten year old niece Cindy Sue while her parents are on a skiing trip. Since the honest little girl won't allow for him to do nothing crooked, Boss asks the Dukes for a 'truce' and dumps the little girl on them while goes to do some business in Viena.
The Dukes meet young Peppino and his racing horse El Blanco while driving through Spain. Boss Hogg is in league with a rival horse racer, Señor Geraldo, owner of the competing horse El Diablo, who asks him to kidnap El Blanco.
Uncle Jesse finds old Great-Uncle Cyrus Duke's treasure map and heads to the Philipines where his Cousins are racing, to find Cyrus' treasure. However it is hidden in a swamp that is supposed to be haunted by a hairy monster.