Purpose: To evaluate caries among nursery-school children. Materials and Methods: Clinical examination was carried out in 1123 children (568 girls and 555 boys), aged 6-47 months, who attended 33 nursery schools located in a large city (Poznan, Poland). The research was done by experienced dentists in accordance with the criteria set by the World Health Organization for epidemiological studies. The obtained data determined the frequency of caries and the number and surfaces of teeth with carious lesions. In Poznan, drinking water is not artificially fluoridated. Results: The prevalence of caries in the general population was 7.21%. The mean number of teeth affected by caries in the whole population was 0.26 (0.24 for girls and 0.28 for boys), whereas the mean number of tooth surfaces affected by caries was 0.37 (0.32 and 0.41, respectively). In the maxilla, most of the carious lesions were located in the incisors; in contrast, in the mandible, they were in the molars. Only 3 of the examined children had prior fillings. Conclusions: Currently, preventive and curative dental care for nursery-school-age children is unsatisfactory. The results obtained indicate the need for monitoring the oral health of young children. Keywords: children, drinking water, early childhood caries, fluoride, nursery schools