Assemblages of subfossil molluscs were found in Pleistocene and Holocene deposits in Muselievo (Northern Bulgaria). The fauna of the loess and loess-like loams included land snails typical of a relatively warm climate and dry, open habitats. Only the uppermost part of the profile contained an assemblage similar to those described from loess of Central Europe. The mollusc fauna of the Holocene deposits forming the terrace of the Osam River was distinctly richer. It reflects changes in sedimentary conditions and habitat types during the Subboreal and Subatlantic phases. The similarity of the assemblages from the two stratigraphical units suggests that climatic differences between particular warm and cold phases were much less pronounced in the Balkan Peninsula, compared to Central Europe.