Although the Brdy Protected Landscape Area is located not far from Prague on the border between central and western Bohemia, there was very little published and unpublished data on its aquatic malacofauna. For this reason, a more detailed survey of aquatic molluscs was carried out in 2020–2022. Altogether with previous data, 27 species were found at 108 studied sites, including springs, small streams, fishponds, pools, and wetlands. The low species diversity is related to not very suitable natural conditions. The occurrences of only 1–2 species of aquatic molluscs were found at 72 out of 108 studied sites. Two species (Radix labiata, Pisidium casertanum) are typical for nutrient-poor habitats. The more rich molluscan assemblages were detected only in the peripheral parts of the Brdy Mts. and/or in the Padrť region with numerous fishponds and associated wetlands. Most (18) of the detected species belong to common and widespread molluscs. Three non-native species (Physa acuta, Ferrissia californica, Sinanodonta woodiana) were found.