Rich and diverse mollusc assemblages occur in Upper Holocene sand and mud developed near Korytnica in the southern margin of the Świętokrzyskie Mts. Four profiles of these sediments have been found in the valley of a small stream, ca. 1–1.5 km W of the village centre. Three types of assemblages can be distinguished. The first, occurring in alluvial deposits forming the lower terrace of the stream, has a considerable proportion of land snails, especially woodland species. The second corresponds with the development of a small fish-pond, in existence since the 19th c. till World War II, and is dominated by water molluscs. The third malacocenosis is associated with the last phase of filling, overgrowing and drainage of the fish-pond. Open-country, mesophile and higrophile species are its main components. The succession of mollusc assemblages indicates changes of palaeogeographic conditions during the last phase of the Holocene controlled mainly by human impact.