The inherent technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. These countries have a great and ever-intensifying need for power and water supplies and they also have the greatest remaining hydro potential. Development is a basic human right, as few would deny. Energy policymakers must meet their responsibility in exploring the most rational options for meeting the energy needs of the developing countries, while protecting the environment to the maximum possible extent. Technically, feasible hydropower estimated at nearly 15,000 TWh/yr still exists in the world today, mostly in countries where increased power supplies from clean and renewable sources are most urgently needed to progress social and economic development. This paper reviews the current role hydropower is playing in the world, along with some its inherent benefits, and then looks at the remaining potential, and some specific development plans in various countries of the world.