The European Union is a ‘split-level democracy’, whereby the basic democratic legitimizing mechanisms are split between supranational and national levels of governance. Empirical research documents that citizens also split their tickets across the EU’s electoral arenas. The reasons, however, behind this political behavior are as yet contested. And while the extent to which issue congruence matters for ticket-splitting remain debatable, studies of the EU further disagree on which dimension is more important for issue congruence. Hence, we examine the extent to which issue congruence matters for ticket-splitting in two dimensions of conflict (left-right and EU). Drawing on previous works and progressively relaxing the congruence assumption, we identify three types of ticket-splitting and test the effects of EU and LR congruence, EU media coverage, EU polarization, electoral rules and timing of EP election. Our analysis sheds new light on causes of voters’ split-ticketing and consequently of different outcomes across electoral arenas.