Aquatic molluscs of three extensive nature reserves (Žabakor, Podtrosecká údolí, Údolí Plakánek) in the Český ráj Protected Landscape Area (northern Bohemia) were studied in 2019. Altogether 33 mollusc species were found at 40 studied sites including streams, fishponds, pools, and wetlands. Results were compared with previous research. The occurrence of endangered bivalves Sphaerium nucleus and Pisidium amnicum was confirmed. Two non-native species Physa acuta and Ferrissia californica were recorded.