This article examines the development of mutual recognition of marketing authorizations for pharmaceuticals, arguing that the sui generis approach to mutual recognition in this policy area is based, first of all, on the harmonisation of regulatory requirements. However, it additionally also required the procedural integration of mutual recognition in trans-national administrative procedures, and institutional innovation. This has created a curious mix of centralized and decentralized authorisation routes with various stages of collaboration and arbitration. In this regard, the creation of the complex, composite procedures in place to facilitate the mutual recognition of pharmaceuticals raises several questions with regard to the judicial and political accountability of the actors involved. The developments and problems described in this article with regard to pharmaceuticals are also mirrored in other risk regulation areas, where mutual recognition seems to require the integration into administrative procedures on intra-administrative and/or EU level, leading to proliferation of sui generis approaches to mutual recognition.