In recent years it has been recognised by an increasing number of nations that there is considerable energy potential within MSW. As a result many countries have established R,D& D programmes to examine methods of exploiting this potential. The IEA's MSW Conversion Activity was set up in 1986 to provide an infrastructure for sharing information and co-ordinating work in this area internationally. This Activity was extended in 1989 and currently a total of 9 nations participate in it. To cope with the wide scope of the area (encompassing both biological and thermal processing of MSW) the Activity was divided into three subgroups or Expert Working Groups (EWGs). Each of these dealt with a distinct area of expertise: . Downstream effects of source separation and screening of MSW . Sampling and analytical protocols . Landfill gas In addition to these groups a central secretariat based at Harwell (UK) has provided guidance, established and administered databases of contacts and produced a series of national reports. This paper describes the achievements of the Activity and discusses work proposed for the future.