On the ground of the increasingly alarming pollution situation in Asian countries, a systematic approach to the energy-environment planning is urgently needed. This document "Guide book on Energy Environment Planning in Developing Countries: Synthesis Report on Economic Sustainability and Environmental Betterment through Saving and Fuel Switching in Developing Countries", has been prepared to give a view on the overall energy and environmental situation in several Asian developing countries and to provide elements of the energy-environment approaches to the participants of the Regional Workshop on "Application of Methodologies and Tools to Evaluate Environmental Impacts of National Energy Demand through Energy Conservation and Fuel Switching", being held at AIT from January 22 to January 26 1996, within the framework of the Programme for Asian Cooperation on Energy and the Environment (PACE-E).