Although the concept of policy transfer attracts growing attention in political science, its application to the European Union remains underdeveloped. This article offers a comprehensive conceptual account of EU policy transfer. It starts from the institutionalist premise that transfer processes and outcomes will vary between differently constituted governance regimes. Three forms of EU governance are identified; hierarchy, negotiation and 'facilitated unilateralism'. The article develops hypotheses about the linkages between institutional variables and transfer outcomes, assessed on a scale from emulation to influence. Hypotheses are set against empirical evidence drawn from a variety of policy areas. We find evidence to support the general hypothesis that stronger forms of policy transfer occur in more highly institutionalized governance regimes. The evidence also points to micro-institutional variables shaping transfer outcomes: the powers accruing to supra-national institutions; decision rules; and the density of exchange between national actors.