The people's perception on environmental and socio-economic impacts due to three hydro-electric projects (HEPs; commissioned and under construction) were studied in the north-west Indian Himalaya. Surveys among 140 project-affected people (PAPs) using a checklist of impacts indicate that among the negative impacts, decrease in flora/fauna, agriculture, flow of river, aesthetic beauty; and increase in water pollution, river bed quarrying for sand/stone, human settlement on river banks and social evils; and among the positive impacts, increase in standard of living, road connectivity, means of transport, public amenities, tourism and environmental awareness were related with HEPs. The PAPs tend to forget the negative impacts with the age of the HEPs after it becomes functional, and the positive impacts seem to outweigh the negative impacts. Study concludes that it is difficult to separate the compounding impacts due to HEP construction and other anthropogenic and natural factors, and in the absence of cause-and-effect analyses, it is hard to dispel the prevailing notion that HEPs are undesirable in the study area that led to agitations by the environmentalists and stopped construction of one of these HEPs. To overcome the situation, multi-disciplinary scientific studies involving the PAPs need to be carried out in planning and decision-making to make HEPs environment friendly and sustainable in this region. There is also a need to adopt low carbon electric power technologies and promote a decentralized energy strategy through joint ventures between public and private companies utilizing locally available renewable energy resources.