Emergency physicians (EPs) are increasingly participating in international medicine in regions that are chronically medically underserved. In August 1994, a ten-member emergency medicine team from the Loma Linda University School of Medicine staffed a 70-bed bush hospital in the primitive highlands of Papua New Guinea, providing both outpatient and inpatient medical care. Typhoid fever, malaria, polio, and numerous other infectious diseases were encountered. Rampant local tribal warfare resulted in regular penetrating injuries from arrows, spears, and machetes. The expedition was judged highly successful, in that 1) substantial medical service was provided to tribespeople accustomed to minimal care, 2) education was provided to local health care providers, and 3) team participants became adept at managing medical conditions uncommon in industrialized societies, and gained valuable ethical and utilitarian perspectives regarding health care delivery in underserved areas. In this article the objectives, organization, and experiences of the team members are described. This information may encourage other EPs to participate in medical expeditions to the developing world, and to provide general principles to assist in their organization and implementation.