Who gets what in bargaining between states and international organizations (IOs)? Although distributional conflict is unavoidable in international cooperation, previous research provides few empirical insights into the determinants of bargaining outcomes. We test a simple bargaining model of cooperation between states and IOs. We expect that nonegalitarian international organizations, such as the World Bank, secure more gains from bargaining with economically weak than with economically powerful states. For egalitarian international organizations, such as most United Nations (UN) agencies, the state’s economic power should be less important. We test these hypotheses against a novel data set on funding shares for 2255 projects implemented under the auspices of the Global Environment Facility, from1991 to 2011. The data allow us to directly measure bargaining outcomes. The results highlight the importance of accounting for the interactive effects of international organization and state characteristics.