The authors examine regional cooperation among neighboring countries in the area of regional public goods. These public goods include water basins (such as lakes, rivers, and underground water), infrastructure (such as roads, railways, and dams), energy, and the environment. Their analysis focuses on developing countries and the potentially beneficial role that international organizations and regional integration may play in bringing the relevant countries to a cooperative equilibrium. A major problem in reaching a cooperative solution is likely to be the lack of trust. If neighboring countries do not trust each other because of past problems, they may fail to reach a cooperative solution as each tries to maximize its gain from the regional public good. These strategies typically do not account for spillover effects and ultimately leads to losses for all parties. Other constraints on reaching a cooperative solution are its complexity and the financial requirements. Two types of institutions may help resolve some or all of these problems. International organizations can help with trust, expertise, and financing. The United Nations and the World Bank have been involved in a number of such projects in Africa, Asia, and elsewhere, and have been successful in helping parties reach cooperative solutions. Regional integration agreements, though not necessary for regional cooperation, may also be helpful by embedding the negotiations on regional cooperation in a broader institutional framework. The authors examine these issues with the support of both analysis and a number of case studies.