This paper examines European Union (EU) causal mechanisms and policy instruments affecting the urban domain throughout the lenses of the Europeanization approach. Instead of looking at EU instruments that are formally/legally consecrated to cities, we use theoretical public policy analysis to explore the arenas and the causal mechanisms that structure the encounters between the EU and urban systems of governance. Policy instruments are related to policy arenas and in turn to different mechanisms of transmission thus originating a typology of European Policy Modes. Empirically, the paper focuses on the issue areas of waste management and air quality control via the analysis of the Packaging waste Directive and the 1999/30 Directive on limit emission. In the conclusions we highlight the differences between this approach and the traditional analysis of EU urban policy, and suggest avenues for future empirical research based on typologies of policy instruments and modes of Europeanization.