Evaluation of dental caries and fluorosis prevalence of children in Eskisehir Background: This study aimed to evaluate the prevalence of the dental caries and dental fluorosis in children living in Eskişehir. The etiological factors of the dental fluorosis and the correlation of the prevalence of dental fluorosis between dental caries were also determined. Methods: 4936 children between 8-12 years-old in Eskişehir were included. dft/DMFT and Thylstrup-Fejerskov index were used for the evaluation of the dental caries and fluorosis. Furthermore, the parents of the children were asked to fulfill an anamnesis form including the etiological factors, which were considered as the possible cause of the dental fluorosis. The fluoride concentrations of the drinking water were determined by the ion-chromatography. Statistical analysis was performed using Mann Whitney-U, Kruskal Wallis and the Spearman's Correlation Tests. Results: The mean DMFT score was 2.18±2.00, dental fluorosis prevalence was 1.9 % in the participating children. There was a significant difference between the towns regarding the prevalence of the dental fluorosis (p<0.001). The highest prevalence of dental fluorosis was determined in Çifteler (15.2 %), where the flour concentration in the water was above the optimal dose. A negative correlation was determined between the prevalence of the dental fluorosis and caries (p<0.01). Furthermore, a significant correlation was also determined between the dental fluorosis and the parental education level, living in the same region since birth, duration of the feeding with the mother's milk, the type of the drinking water, the type of the water used in the school and the type of the toothpaste (p<0.05). Conclusion: We conclude that along with the fluoride concentration in the drinking water also other factors such as the duration of the feeding with the mother's milk and the type of the used toothpaste are playing an important role in the prevalence of the dental fluorosis and all etiological factors should be taken into the consideration for the prevention it.