Two subfossil mollusc assemblages have been found near Sromowce, occurring in sediments of the Late Holocene. The older assemblage occurs in sediments dated to the V-XII centuries AD, and the younger one is connected with the sediments created in the two most recent centuries. The former comprises numerous species of forest and mesophilous snails and mass agglomerations of Bythinella austriaca shells. The presence of such a fauna indicates that in the Early Middle Ages, the southward slopes of the main range of the Pieniny Mountains were almost completely afforested. The dominants in the latter assemblage are typical snails of open habitats. The alteration of the malacofauna, being due to the deforestation of a considerable area, reflects a transformation of the natural environment under human impact.