The population structure in most European countries is currently changing, with a shift from younger to older age groups. Only sparse data exist on the impact of these demographic changes on future blood demand and supply. Data on blood recipients are sparse and unconnected to data on blood donors. The first part of this review summarizes studies on the effect of the demographic change on blood supply and demand. With respect to studies in North America and Europe on the impact of demographic changes on future blood supply, the demographic trends will affect many regions in the Western world similarly. These effects are most pronounced in the new member states of the European Union where birth rates declined abruptly after 1989. Coordinated efforts will be required to prevent blood shortages based upon these demographic trends in Western societies. The second part of this review is an overview of methodological approaches to obtain data on the sociodemographic background of the blood donor population.