Abstract This article presents a case study on the differential marking of direct objects (DOM) in Balkan Judeo-Spanish, an endangered language (sub)group that still lacks detailed, systematic documentation of its (comparative) morphosyntax. Countering recent claims that the phenomenon is frequently absent in Judeo-Spanish, I demonstrate the robust presence of so-called a-marking as a highly systematic, multi-dimensional DOM strategy in early 20th century fieldwork recordings from the understudied dialect of Monastir (present-day Bitola, North Macedonia). I show that, in our corpus, a-marking in transitive (S)V(S)O(S) structures is primarily regulated by (grammatical) animacy/person and (syntactic) definiteness, such that indefinite DOs are excluded and specificity plays no role. Theoretically, the empirical distribution of a-marking broadly conforms with, yet – crucially – cannot be fully subsumed under, scale-based hierarchies that model DOM in terms of referential prominence. Rather, our findings support the conclusion that a-marking of the DO occurs if and only if the argument is syntactically specified for animacy/person and definiteness. From the typological perspective, the (non-)coincidence of Monastirli a-marking with a co-referential accusative clitic exhibits a hitherto undescribed distribution distinct from other patterns documented for (Balkan) Romance. The present article thus not only advances description of, and inquiry into, the cross-linguistic landscape of DOM, but contributes more broadly to redressing the conspicuous absence of empirical and theoretical investigation into Judeo-Spanish dialect syntax.