In this brief contribution to the debate on Europeanization, we further expand previous work on the proportion of Swiss domestic legislation that is influenced by the EU (Gava and Varone 2012). In so doing, we focus on questions of considerable normative implications: To what extent are policy changes traceable in legal reforms “infiltrated” by the EU? Is the EU's footprint higher in primary legislation (enacted by Parliament) or in secondary legislation (enacted essentially by the Executive)? Do these linkages result from bilateral agreements (i.e. direct Europeanization) or indirect Europeanization processes? How do policy sectors differ in this regard?