Transboundary watercourses pose a variety of challenges to the management of water resources. Basin-wide management approaches often clash with state sovereignty. Efforts in cooperatively managing shared water resources are therefore of great importance for the sustainable management of transboundary river and lake basins. The World Bank has long been engaged in transboundary water resources management starting with the support to the establishment of the Indus Treaty signed between India and Pakistan in 1960 and followed by numerous other important initiatives and projects on transboundary watercourses. The results of the report reveal significant differences in institutional resilience to climate changeinduced water variability across transboundary basins, with some basins being fairly resilient to climate change on all five dimensions identified as decisive for climate change resilience while others, especially in EAP and LCR, face a range of challenges.