Water, a limited finite resource, vital for the very existence of life on earth and a necessity for economic and social development and for environmental sustainability, is becoming a scarce commodity. This is caused by the population growth, the change of lifestyle, water pollution caused by human intervention, inefficient use of water and climatic changes with more frequent extreme events such as droughts and floods. Where the availability of water cannot be increased by using conventional resources or by recycling or cannot be made available by demand management methods, the desalination of sea or brackish water offers an alternative solution. The desalination of water has been practiced since ancient times but was not widely used due to technological limitations, the prohibitive high capital costs, high-energy consumption and finally very high unit cost when compared to conventional water. New technological advances in the last 30 years tremendously reduced the capital cost and the energy consumption so that desalination projects can be considered as alternative solutions to water development. However, desalination projects are still not very cheap to be easily accommodated by the economies of many countries, energy consumption is still comparatively high, and acceptance of such projects is questioned by environmentalist, politicians, engineers and other groups of the population on economic, social and environmental issues. The present paper outlines the growth of desalination worldwide, the reasons why it is growing, whether it is a solution to the water scarcity problem, and what are desalination and desalination and the environment. It also considers the social acceptance of the plant, steps for scientific, engineering, social and environmental acceptance and environmental mitigation measures and the energy demand and alternative sources of energy. Environmental effects on the sea environment, the air, land and on the region as well as on the regional development plans are to be minimized. Finally the costs are to be considered including the effects on the total economy of the country and the financing options.