Osteoporosis is a global problem which will increase in significance as the population of the world both increases and ages. This report looks at how the demographic changes in different countries of the world will be reflected in the incidence and cost of osteoporotic disease. Comparisons are made between the data collected by the European Union's Report on Osteoporosis in the European Community, issued in June 1998, and some of the data available from other parts of the world. The importance of prevention, early detection and appropriate treatment is stressed, as well as the need for national health services to provide reimbursement of the costs of prevention, diagnosis and treatment for high-risk groups.