This paper conceptualizes the implementation of (quasi-)judicial decisions on environmental disputes in the European Union from a concept-structural perspective. It provides an integrated analytical framework which illustrates both the conceptual basis for comparing implementation processes in a variety of supranational disputes, as well as possible explanatory paths following a conjunctural logic. This approach considers the various structural, procedural, and context conditions at different levels of governance relevant to legal implementation. While legal frameworks at the national level are usually dense, European Union law implies its own unique implementation setting, which is highly relevant in environmental disputes, especially considering the high politics of climate change. First, existing research on the implementation of environmental decisions is discussed. Second, a concept-structural framework is developed to both theorize the implementation of decisions, and to provide an integrated analytical framework for further analysis. Finally, empirical examples are introduced to illustrate the viability of this approach.