When a retired opera singer leaves her inheritance to her cat, Duchess (Eva Gabor), and three kittens, the woman's butler drugs the cats and abandons them in the countryside in order to inherit the fortune himself. Lost in unfamiliar territory, Duchess and the kittens meet Thomas O'Malley (Phil Harris), an alley cat willing to help them return to their home in Paris. They meet several kooky characters along the way, including two English geese and an alley cat jazz band.