The environmental impact of energy production and use with the associated emissions of greenhouse gases, particularly CO2, has created much attention and growing concern at both national and international levels. In Egypt, efforts have been directed to incorporate the environment-protection issues within the overall planning of the energy sector, as appropriate to its national commitment and its techno-economic considerations. Over the past decade, 1985-1995, hydro-power had contributed between 28 and 22% of the total energy produced by Egyptian power-plants, while the contribution of the hydro capacity was between 32.4 and 21.5%. Many studies have been carried out on the impacts of the Aswan High Dam on various aspects of the environment. An objective evaluation of the Dam, based on 25 years of operational data, indicated that it has overall been positive even though it has contributed to some environmental problems. These problems, however, are significantly less than most people originally expected. This paper deals with the review and analysis of the detrimental effects of hydro-power in Egypt. An evaluation will be given of the emissions of greenhouse gases from the whole hydro-chain.