Purpose: The aim of this study was to identify the prevalence and severity of caries and of early childhood caries (ECC) in preschool children from the municipality of Capivari de Baixo, Brazil. Furthermore, the aim was to ascertain the association between these prevalences and the level of maternal schooling. Materials and Methods: A cross-sectional study was performed involving all children aged 3 to 5 years enrolled in all municipal schools of Capivari de Baixo, Brazil. The clinical information was obtained using the World Health Organization criteria. For ECC, it was observed if the child presented with lesions with acute evolution, whitening clinical aspect and softened consistency. Non-clinical data were obtained by means of interviews with the child's mothers, by investigating the child and through questions relating to the maternal age, the maternal level of schooling and the time of weaning. Tests of association were performed using the chi-square test followed by unconditional multiple logistic regression analysis to test the independence of the association between the outcomes and the explanatory variables. Results: The prevalence of caries was 64.3%, the mean dmft was 1.24 and the prevalence of ECC was 4.9%. A child was more likely to present with severe caries (dmft ≥ 2) if aged 47 months or above. Low maternal schooling made the occurrence of both severe caries and ECC more likely. Conclusions: The population that was studied presented levels of oral health better than those found in other Brazilian population groups, although groups remain with a high severity of caries associated with low maternal schooling. Keywords: dental caries, early childhood caries, infectious disease, schooling, socioeconomic status