In April 1994, resumption of a longstanding conflict between the Hutus and Tutsis--the two major ethnic groups in the central African countries of Burundi and Zaire--resulted in civil war and mass genocide in Rwanda. An estimated 63,000 (primarily Tutsi) refugees subsequently moved from Rwanda into northern Burundi, and 500,000 refugees fled to Tanzania (Figure 1). In early July 1994, as armed strife subsided, many Tutsis returned home to Rwanda, and an estimated 1 million Rwandan Hutus fled to Zaire, and 170,000 fled to Burundi. To monitor the health status of the refugees, the Office of the United Nations High Commissioner for Refugees (UNHCR) and nongovernmental organizations (NGOs) working in refugee camps in both countries established systems for rapid surveillance of morbidity and mortality. This report presents the findings of these systems during May-September 1994 (the period of the most intensive population migration) and indicates that mortality was high among refugees in camps in both countries.