The aim of the article is to describe popular surnames of the residents of the Hajnowka district in the early 21st century. The object of analysis is the surnames that, with regard to the number of their bearers, occupy the 20th to 40th position. The following surnames have been analyzed: Pawluczuk, Sawczuk, Sacharczuk, Wołkowycki, Sadowski, Gawryluk, Leoniuk, Oniszczuk, Daniluk, Jakoniuk, Niczyporuk, Jakubowski, Fiedoruk, Jakimiuk, Androsiuk, Sajewicz, Ostaszewski, Roszczenko, Romańczuk, Sidoruk. The surnames are described according to the following patterns: a) dialectal pronunciation of the surname, b) the number of bearers of the surname in Poland, c) the distribution of the surname, d) populations of bearers of the surname in the Podlaskie voivodeship, e) larger populations of the surname bearers outside of the Podlaskie voivodeship, f) the number of the surname bearers in the Hajnowka district, g) the percentage of the surname bearers in the Hajnowka district compared to the whole country, h) the position of the Hajnowka district in Poland with regard to the number of bearers of the surname, i) probable etymologies and motivations of the surname, j) cognate surnames. A separate publication was devoted to the most popular names in the Hajnowka district in the early 21 st century, where the author described 20 anthroponyms. The analysis of the anthroponymic material shows that the surname system of the Hajnowka district residents has largely preserved its traditional East Slavic character. The prevailing ones here are patronymic surnames, predominant in the East Slavic areas, which are related to names of Greek origin. This system contains features typical of individual East Slavic languages and of the Polish language, which played a significant role in its formation.