The aim of this paper is to highlight certain similarities between Polish and Bulgarian with respect to the selected NP/DP criteria compiled by Bošković (2012. On NPs and clauses. In Günther Grewendorf & Thomas Ede Zimmermann (eds.), Discourse and grammar: From sentence types to lexical categories , 179–242. Berlin: De Gruyter). In the course of the discussion, Negative Raising with idioms and quantifier – negation interaction, definite/indefinite contrasts in the context of sub-extraction, as well as exhaustive presupposition are taken into consideration. On the basis of the data, I put forward an analysis of the Polish facts which draws upon Tasseva-Kurktchieva and Dubinsky’s (2018. On the NP/DP frontier: Bulgarian as a transitional case. In Steven Franks, Virinda Chidambaram, Brian Joseph & Ilyana Krapova (eds.), Studies in Bulgarian Morphosyntax in Honor of Catherine Rudin , 287–312. Bloomington, IN: Slavica) account of the DEF(initeness) feature on the D head (which they use to argue for Bulgarian as a ‘weak’ DP language). Despite certain similarities between the two languages, Polish actually seems to resemble English in terms of the specific coding of this feature. The analysis suggests that (unlike in Bulgarian) DEF on D in Polish is not intrinsically valued (+int, +val), but rather receives a specific value in the course of the syntactic derivation.