Summary : This monograph brings together national malaria databases for 1996, 1997 and 1998 from the 6 countries comprising the Greater Mekong Subregion of Southeast Asia: Cambodia, China (southern provinces), Lao People's Democratic Republic, Myanmar, Thailand, Viet Nam. The objective is to create a regional perspective in what is a global epicenter of drug resistant falciparum malaria, so to enhance the information flow required to improve malaria control on a regional basis in the context of economic and social change. Geographical Information Systems technology has been applied to the regional mapping of total reported malaria cases, malaria incidence, confirmed cases, parasite species distribution. There is great diversity in disease patterns in the 6 countries and at subnational administrative unit area level in each country, so that in the region as a whole there is marked asymmetry in disease distribution, with many areas of high endemicity.