This article provides a comparative analysis of the degree of Europeanization of national party manifestos. The research is based on a newly established database, which comprises digitized party manifestos of relevant parties in the period 1960-2003 in most of the established member states. The unit of analysis is the frequency of 'co-mentions' of 20 policy areas and (aspects of) Europe and the European Union. The results show that the degree to which parties acknowledge the increasing impact of Europe on policy-making depends on factors such as the time period, the type of policy sector, the duration of EU membership, the general attitude of parties towards European integration and the degree of internal consensus on European issues. Hence, references to Europe do not (only) reflect the process of European integration itself, but are affected by both insti tutional and party strategic factors. Copyright © 2006 Sage Publications.