Abstract Objective of the study: evaluation of the state of dental health in children from ecologically unfavorable areas. Materials and methods: 758 children between the ages of 7 and 16 were clinically examined in the case-control study. The research group (L1) included 379 children who live permanently in environmentally unfavorable areas. The control group (L0) consisted of 379 children from ecologically favorable areas. Prevalence indices of dental caries and developmental defects of tooth enamel were assessed. The research was carried out in accordance with the ethical requirements while obtaining the written consent of the parents for the participation of the children in the study. Results: in children from ecologically unfavorable areas, the prevalence indices of dental caries and developmental defects of dental enamel were significantly higher, compared to controls: the prevalence of dental caries was 1.65 times higher, and the prevalence of developmental defects of tooth enamel, respectively, 20.3 times higher. Conclusions: the increased prevalence of dental enamel developmental defects estimated in children from ecologically unfavorable areas could reflect the impact of harmful environmental factors on dental health and can be used by specialists and local authorities to prioritize initiatives to improve population health. Key words: enamel development defects, dental caries, ecologically unfavorable areas.