This paper discusses methodological lessons and empirical results of climate change mitigation assessment for developing countries with a special emphasis on economic studies, National study results are discussed in relation to expected general international development trends in greenhouse gas emissions. It is concluded that greenhouse gas emissions from developing countries certainly will increase in the future due to economic development needs. There is however a large and relatively cheap potential for emission reductions connected to efficiency improvements in industrial production and general energy efficiency improvements in the countries. The implementation of greenhouse gas mitigation strategies is interrelated with general national economic development policies. The macroeconomic impact of implementing climate change mititgation strategies is assessed on the basis of two case studies for Zimbabwe and Venezuela and it is concluded that project implementation and economic welfare improvement in some cases can be achieved simultaneously. The methodological basis for macroeconomic assessment and for the establishment of baseline scenarios are critically discussed in relation to the specific planning context of developing countries and recommendations are given on research requirements.