The Baltic Sea Region is subject to international regulation at the global level, through EU legislation, and sub-regionally. This article aims is to identify features of the regulatory framework both in terms of the nature of core legal instruments and the role of intergovernmental organizations. As the article seeks to identify interconnections between the regulatory layers, the role of EU law for Baltic Sea cooperation warrants special attention. EU law, the article claims, not only comes with a promise of monitoring and enforcement, but can also be a main source of diffusion of the regulatory process. Further, while EU law structures the regulatory scene in accordance with EU competence, it excludes one Baltic Sea littoral state – the Russian Federation. For this reason alone, the global and regional levels retain their importance, underlining also the importance of regulatory interaction.