The actual impact of judicial decisions often depends on the behavior of executive and legislative bodies that implement the rulings. Consequently, when a court hears a case involving the interests of those controlling the executive and legislative institutions, those interests can threaten to obstruct the court's intended outcome. In this paper, we evaluate whether and to what extent such constraints shape judicial rulings. Specifically, we examine how threats of noncompliance and legislative override influence decisions by the European Court of Justice (ECJ). Based on a statistical analysis of a novel dataset of ECJ rulings, we find that the preferences of member-state governments—whose interests are central to threats of noncompliance and override—have a systematic and substantively important impact on ECJ decisions.