Natural disasters continue to be a major cause of morbidity and mortality. Natural disaster epidemiology has led not only to the scientific measurement and description of disaster-associated health effects, but also to strategies for preventing adverse health consequences and improving post-impact health care delivery. Results of epidemiologic studies of natural disasters provide clues to diagnosis, help medical care providers match resources to needs, and permit better contingency planning. Well-documented medical records are an essential resource for disaster epidemiologists. Cooperation between health care personnel and epidemiologists can help lessen the public health impacts of natural disasters.