The planning and estimation of future energy demand via modern statistical methods have been officially used in Turkey since 1984. However, almost all previous forecasts proved significantly higher than actual observations because of several reasons discussed here. The cycle analysis, which is a semi-statistical technique that makes use of any cyclicity in the historical data of annual additional amounts of energy demand, appears to give better results than the other techniques for forecasting energy demand in Turkey. This method suggests that the energy demand will be around 130 million toe in 2010. This figure is very close to the estimates obtained by the Winter's exponential smoothing method. To increase the scientific validity of the method, it should be applied in other similar countries. (C) 2001 Elsevier Science Ltd. All rights reserved.