This article describes the etymology of the Sokółka district’s microtoponyms containing the word stem var-. In Lithuanian source literature, names with the var- component are connected with hydrographic elements. The author directs attention to a borderland nature of the analyzed region. The Sokółka district is located in the central part of Podlaskie Voivodeship, next to the Belarusian border. Since time immemorial, it has been a place where Baltic and Slavonic peoples came into contact with Eastern and Western Slavs. Ethnically and linguistically diversified settlement processes concerning the discussed region are reflected in place names. Not only Polish place names, but also those of East Slavic and Baltic origins can be found there.
In the article the author analysed historical place names of the Sokólski district. Historical documentation of the onomastic material dates back from XVI to XX century. It includes published sources, manuscripts and historical maps of the region. The semantic and formative analysis of the material was conducted. It was proved that diverse settlement influenced the place names of this region. The lexical base for these names is formed on the basis of the Polish, Belorussian and Baltic common nouns and anthroponyms. Some names of the former settlements or villages were identified and localized as place names at present.