It is estimated that in excess of 300,000 children are born each year with a severe inherited disorder of hemoglobin and that approximately 80% of these births occur in low- or middle-income countries. As these countries go through an epidemiologic transition, with a reduction in childhood and infant mortality due to improved public health measures, babies who would have previously died of these diseases before they were recognized are now surviving to present for diagnosis and treatment. Hence, they are presenting an increasing global health burden. Because of their uneven distribution in high-frequency populations, reflecting their complex population genetics, the true magnitude of this burden is still unknown. In many poor countries there are virtually no facilities for the diagnosis and management of these conditions, and even in richer countries there are limited data about their frequency, clinical course, or mortality. Without this information, it will be impossible to persuade governments about the increasing importance of these diseases. The situation will only be improved by concerted action on the part of the hematology community of the richer countries together with input from the major international health organizations and funding agencies.