The UNECE Convention on the Protection and Use of Transboundary Watercourses and International Lakes of 1992 places a significant emphasis on institutional cooperation between countries. It requires countries to enter into agreements and to establish joint bodies, such as river basin commissions and other institutions for transboundary water cooperation. This publication analyses structures and activities of joint bodies for transboundary water cooperation and presents recommendations for developing cooperation and establishing and improving joint bodies in the countries of Eastern Europe, Caucasus and Central Asia. It focuses particularly on aspects where existing joint bodies in Eastern Europe, Caucasus and Central Asia could improve their activities by strengthening institutional mechanisms. It describes major challenges and perspectives for cooperation in specific river basins.