The paper discusses lexical borrowings from Polish in Belarusian dialects of East and East-South Lithuania. The dialectological material has been collected from members of the oldest generation, living in villages (years 2009–2016) and selected from The Dictionary of the Belarusian Dialects of North-West Belarus. The borrowings refer to various aspects of life, e.g. nature, traditional farming, breeding, fishing, household and rural buildings, Catholic church, the sphere of administration and education, vocabulary connected to Polish culture and landowners, medicine, family relationship and other.