The authors present the results of stomatological epidemiological studies in the Province of Poznán in 1987 for establishing the prevalence of dental caries in children aged 7 and 12 years. The assessment was done using the index of caries prevalence, value of the mean DMF-H and dmf-h indices, and their components. In both studied age groups a high prevalence of caries was found, reaching 90% in children aged 7, years and 80% in those aged 12 years. The intensity of caries in children aged 7 years measured by the index DMF-h+dmf-h (mixed teeth) was high--4.99. The intensity of caries was higher in children from rural areas (5.43) than in those from urban areas (4.455). The mean value of DMF-h was 0.49 for the whole population studied, and 0.41 for urban children and 0.56 for rural children. The mean DMF-z value in children aged 12 years was below 3.0 (2.34), and it was higher in children from rural areas (2.96) than in those from urban areas. The values of these indices were influenced mainly by high mean numbers of milk and permanent teeth with active caries. In the studied population a small number of filled teeth was noted.