ABSTRACT Whether European leaders ‘talk the walk’ is a key question in EU studies. Prior research has made substantial inroads into explaining how EU and national leaders communicate about European integration, as well as what positions member states and EU institutions take in EU negotiations and why. However, we do not know to what extent leaders’ communication is congruent with what their negotiators do in Brussels, nor what explains such (in)congruence. This article presents a first dive into these questions. It formulates two theoretical arguments on why leaders’ communication and negotiation positions may diverge: accidentally, due to coordination costs, or intentionally, due to strategic and electoral calculations. Leveraging three novel databases on the Eurozone crisis, we come to two important conclusions: first, the degree of incongruence is substantial and similar to what is found at the national level. Second, our results favour a political-strategic argument for incongruence, but many important questions remain.