European macro-regional strategies (MRS) are established around physical features such as seas, mountain ranges and river basins. They focus on a new type of policy-making area (the ‘macro-regions') while seeking to design and implement innovative governance approaches. They are therefore considered innovative both in their geographical focus (in the context of EU policies) and in their approach to policy design, adoption and implementation. The present article argues that the analysis of this development can usefully be informed by different theories referring to the notion of ‘functions', drawn from political science on the one hand, and from geography and planning on the other. On this basis, it applies a multi-disciplinary perspective to the analysis of the role environmental issues have played in the emergence and adoption of macro-regional strategies. This allows for a comprehensive assessment of the role of environmental issues in the adoption of macro-regional strategies, as well as some of their inherent weaknesses.