The aim of this article is to present the results of linguistic research on peculiarities of the lexicon of the youth of Polish origin in Vilnius. The scope of the project was confined to the lexical stock, and the territory to Vilnius. A series of questionnaire-based surveys was conducted among students of Polish secondary schools in Vilnius as well as undergraduates of Polish philology at Vilnius University and Vilnius Pedagogical University. The collected lingual material was analyzed from the perspective of the influence of Lithuanian languages on the lexicon of the social dialect under investigation. Moreover, peripheral localisms of the Lithuanian origin that feature among the youth of Polish origin in Vilnius are also presented in the research.