The literature on environmental politics and regional governance has mainly been dedicated to the role played by the European Union (EU). The analysis of environmental agenda and politics of other regional international organisations (IOs) and banks remained in the shadows compared to studies of European actors. This book aims to address the following questions: How do various actors (such as regional IOs) matter in promoting an environmental agenda? What challenges do they face? The first perspective developed in this book investigates European IOs (e.g., the EU, the European Bank for Reconstruction and Development) and newly emerged Eurasian IOs (e.g., the Eurasian Economic Union, the Asian Infrastructure Investment Bank). The second perspective unfolds various environmental issues within the EU and across post-Communist EU members and candidate states (e.g., in Serbia, Latvia, Hungary). The analysis of these two perspectives discloses multiple dimensions in the impact of the EU and other regional and non-regional IOs on sustainable development. The book aspires to shed more light on the nexus of political and economic developments, and to contribute to better understanding of the role of a variety of IOs in sustainable development in Europe and Eurasia. The chapters in this book were originally published as a special issue of Post-Communist Economies.