Within Europe, there has been the emergence of an EU-wide nanotechnology regulatory regime with regional authorities gaining greater decision-making power over a wide range of policy areas. However, despite the development of more comprehensive European nanotechnology policies, considerable variation remains in how member states implement these rules and regulations. In this article, we utilize a multi-level governance approach, to explore this seeming paradox in order to explain cross-national policy variation within a common European regulatory framework. This broader analytical approach allows us to account for the wide range of actors involved in European nanotechnology governance including, national governments, international organizations, research institutes, firms, and advocacy groups. Case study analysis of Germany, the United Kingdom, and the Netherlands emphasizes how differences in domestic policy styles explain variation in the implementation of nanotechnology regulations across states. At the same time, the engagement of national governments with European and international regulatory efforts highlights the important role that states play in contributing to the development of a common nanotechnology regime in Europe.