Chronic non-communicable diseases (NCD) account for almost 60% of global mortality, and 80% of deaths from NCD occur in low- and middle-income countries. One quarter of these deaths--almost 9 million in 2005--are in men and women aged <60 years. Taken together, NCD represent globally the single largest cause of mortality in people of working age, and their incidences in younger adults are substantially higher in the poor countries of the world than in the rich. The major causes of NCD-attributable mortality are cardiovascular disease (30% of total global mortality), cancers (13%), chronic respiratory disease (7%) and diabetes (2%). These conditions share a small number of behavioural risk factors, which include a diet high in saturated fat and low in fresh fruit and vegetables, physical inactivity, tobacco smoking, and alcohol excess. In low- and middle-income countries such risk factors tend to be concentrated in urban areas and their prevalences are increasing as a result of rapid urbanization and the increasing globalisation of the food, tobacco and alcohol industries. Because NCD have a major impact on men and women of working age and their elderly dependents, they result in lost income, lost opportunities for investment, and overall lower levels of economic development. Reductions in the incidences of many NCD and their complications are, however, already possible. Up to 80% of all cases of cardiovascular disease or type-2 diabetes and 40% of all cases of cancer, for example, are probably preventable based on current knowledge. In addition, highly cost-effective measures exist for the prevention of some of the complications of established cardiovascular disease and diabetes. Achieving these gains will require a broad range of integrated, population-based interventions as well as measures focused on the individuals at high risk. At present, the international-assistance community provides scant resources for the control of NCD in poor countries, partly, at least, because NCD continue to be wrongly perceived as predominantly diseases of the better off. As urbanization continues apace and populations age, investment in the prevention and control of NCD in low-and middle-income countries can no longer be ignored.