Power is of special significance in a nation's economic development. The rising cost of energy, depleting conventional energy resources and increasing social and environmental constraints against the development of large hydro and concern over pollution from thermal power plants has seen renewed interest in the development of small or micro hydro power projects. The salient features of the micro hydro are short gestation period, environment friendly and inexpensive operation and maintenance. Micro hydro power is perhaps the most reliable of all renewable energy sources which can provide electricity in environmentally benign manner. In fact, a micro hydro system does a similar job to what a solar or wind system does, which is charge batteries. In current scenario, micro hydro systems seem a more cost-effective alternative than a grid connected system. The present publication is a follow up of the International Workshop on The Role of Micro-hydel for Developing Countries organised by the NAM S&T Centre at Kathmandu, Nepal during 19-22 April, 2013 jointly with the the Nepal Academy of Science and Technology (NAST) in collaboration with Alternate Energy Promotion Centre (AEPC). The book includes 19 research papers and status reports from 11 countries, presenting significant insights on role of micro hydro technology in providing wide range of benefits, especially for rural areas and developing countries. It is expected to be of great value for the researcher, professional, experts, non-governmental and governmental organizations working in the field of Small and Micro hydro industries.