The malacofauna of Żywiec was sampled from May to November in 2012 and 2013 in 33 localities. A total of 57 species (one with its form) were recorded: 53 gastropods (40 terrestrial, 13 freshwater) and 4 bivalves. Among them, two protected species (Anodonta cygnea and Trochulus bielzi) and ten listed in the Red List of Threatened Animals in Poland were found. These threatened species are mostly Carpathian in distribution. The molluscan fauna could be separated into two aquatic and six terrestrial ecological groups. Species typical of lakes and reservoirs dominated the aquatic fauna, while woodland species constituted 67% of all terrestrial species. Although woods and sites dominated by Petasites held the most species, and most of those regarded as threatened, even human-induced habitats contained some of the latter. This suggests that fragments of semi-natural habitats constitute important refugia for gastropods within urban environments, among others for the rare and endangered clausiliids Macrogastra tumida, Vestia gulo and V. turgida.