In this paper, the caries prevalence of groups of 8-year-old children in Umeå, Sweden, examined in 1967, 1971, 1975 and 1979 is described. A reduction of caries of 45% in the permanent teeth and 54% in the primary teeth is shown between 1967 and 1979. During the same period there has been a gradual extension of dental care for children and adolescents, and there has been an increasing emphasis on preventive dentistry. The reduction in caries does not, however, continue at the same rapid rate. Further preventive efforts therefore ought to be focused on those individuals with the highest caries indices.