Semi-natural, extensively managed grassland communities are among the most species-rich plant communities. The species number and floristic composition depend on numerous factors, both natural and associated with human activity, both present and past. In European countries, a system of subsidies for farmers is used to preserve extensive, usually unprofitable management of multi-species grassland communities. The development of specific recommendations requires knowledge of the main factors shaping grassland plant communities. A study was carried out in seven regions of the Polish Western Carpathians, in areas with traditional sheep grazing. Plant species composition (phytosociological relevés) of 517 plots were surveyed in different grassland types. For each plot, topographic parameters, i.e. slope, aspect and altitude, were recorded and land use in the past was read from historical maps. The aim of the study was to a) assess differences in the species composition of grassland vegetation between topographically and historically different regions of the Polish Carpathians, and b) to identify the main factors influencing species composition in each of these regions. Depending on the region, different factors contributed most to explaining the variation in the species composition and species numbers. Topographic factors played a decisive role. The type of past use (arable land or grassland) had little influence on current biodiversity. The results of the study indicate the need for a localised approach to developing principles for protection of grassland biodiversity.