The objective of this research is to estimate the energy content of municipal solid waste (MSW) generated in Jordan based on its physical composition. Calorimetric analysis revealed that the average energy content of MSW in Jordan is 2747 kcal/kg. Regression analysis of the measured and the calculated energy content by empirical models shows a good agreement with the models based on the physical composition of MSW. A relationship between the energy content and plastic to paper ratio of MSW was developed and showed that the energy content is directly related to this ratio with a correlation coefficient of 0.94. The energy content of MSW generated in Jordan accounts for 6% of the annual imported oil consumption of the country and may result in annual saving of US$ 24 million in case of utilization. (C) 2000 Elsevier Science Ltd. All rights reserved.