Little is known on the prevalence of sleep disorders and their role in the increased prevalence of cardiovascular diseases in the developing world. We To assess the prevalence of major sleep disorders in a rural South American population, and to determine whether these conditions are associated with a poor cardiovascular health or with the occurrence of stroke or ischemic heart disease. This is a three-phase, population-based, door-to-door survey in Atahualpa. During phase I, all residents aged ≥40 years will be screened with validated Spanish versions of five questionnaires to evaluate major sleep disorders. In phase II, neurologists will examine persons suspected of having a sleep disorder and a random sample of negative individuals to assess the prevalence of these conditions and to validate the accuracy of questionnaires. In phase III, patients with a confirmed sleep disorder will undergo nocturnal polysomnography for achieving a more specific diagnosis. The occurrence of sleep disorders will be correlated with the cardiovascular health of the population as well as with the presence of stroke and ischemic heart disease. This epidemiological study may prove cost-effective in improving sleep conditions of people living in rural areas of developing countries, and may be used as a model for the evaluation of sleep disorders and their cardiovascular correlates in these populations.