The article deals with the study of regionalism in European social anthropology with the focus on Slovakia's regions, regional diversities and identities in a broader perspective of European integration and regionalisation. It looks at socio-anthropological research on regionalism worldwide and in Slovakia particularly. The key objective is to examine the impact of geographical conditions and political-administrative reforms on the development of historic regions, sustainability of regionalism and the survival of regional differences and identities in Slovakia. The essay also discusses the creation of transborder regional co-operation and the establishment of Euroregions that only started to develop in the new democratic conditions after 1989. What do transborder regions mean to local people? Are they only bureaucratically constructed entities based on co-operation of formal authorities or do they also have an impact on people's identities? The essay aims at drawing attention to the importance of this research orientation in contemporary European social anthropology.