Watershed conservation is widely recognized as a major strategy for rural development throughout the developing world. In India, the apparent success of participatory approaches to watershed development resulted in a decentralization of project planning, implementation, and management to local communities at the village scale. We explore the effectiveness of this so-called community-based approach in achieving sustainable soil and water conservation in four semi-arid regions in India, and analyze what factors explain project success. We confirm the result of earlier studies that participatory approaches are more effective in establishing soil and water conservation in the short run. However, our main result is that investments in community organization fail to ensure household commitment to maintenance in the longer term. Without better returns to investment in soil and water conservation and without local institutions to coordinate investment in the long run, the sustainability of participatory watershed management is seriously threatened.