[en] In order to put the prospects for nuclear energy development into perspective, a brief presentation is given of the overall trends in energy demand and supply world-wide. Key issues and factors affecting energy policies and choices between alternative sources are highlighted with emphasis on the electricity sector which is the main market for nuclear energy in short and medium terms. The role that nuclear energy could play in future energy mixes and challenges for nuclear energy development are elaborated. This presentation is based on statistical data and analytical work published by OECD Nuclear Energy Agency, as well as by other authoritative international sources such as International Energy Agency (IEA), the World Energy Council (WEC), and the International Institute of Applied Systems Analysis (ILASA)