The European Union affects the internal organisation of national political parties. We found 'traces of Europe' in the party statutes of all Belgian parties that are represented in the European Parliament since 1999. Europe is, to a greater or lesser extent, present in party goals, rules on party membership and party organs. Parties have elaborated rules for the organisation of European elections, for the selection of European executives, for the formulation of party programmes, and for internal and external co-ordination of policy formulation. At first sight these rules seem to confirm the hypothesis that Europe is in the first place a concern of party leadership, and that it reinforces centralisation of decision-making. Yet the full confirmation of this hypothesis requires further comparative research on the Europeanisation of political parties.