This paper focuses on the syntax of interrogative clauses in Istro-Romanian. The aim is to determine the parametric settings for V-to-C, subject placement (SVO or VSO) and the target for constituent movement under discourse triggers. The findings indicate that Istro-Romanian preserved the parametric settings from Old Romanian, especially those that converged with the parametric settings in Croatian grammar. In particular, SVO can be explained only through inheritance, whereas VSO, lack of V-to-C and scrambling are a matter of both inheritance and convergence with Croatian.