Abstract This study aimed to determine the influence of maternal factors on the early development of dental caries in Brazilian preschoolers. This cross-sectional study was nested in a cohort of adolescent mothers. The current wave was performed when the children were aged 24 to 42 months. The questionnaire-based survey targeted adolescent mothers and included demographic and socioeconomic variables as well as the maternal education level. In addition, clinical examinations were performed on the mothers and their children. Mothers were assessed for decayed, missing and filled teeth in the permanent dentition (DMFT index) and gingival assessment; their children were assessed for decayed, missing and filled teeth in the deciduous dentition (dmft index). Poisson regression with robust variance was used to estimate the prevalence ratio, risk ratio and 95% confidence intervals. This data was also used to identify the maternal risk factors associated with the outcomes (prevalence and severity of childhood caries). A total 538 mother-child dyads were evaluated; the prevalence of early childhood caries was 15.1% and maternal caries was 74.4%. After the adjustment, the children that exhibited a greater incidence of dental caries were from mothers of low socioeconomic status, or from those presenting decayed teeth and higher rates of gingival bleeding. The results of this study suggest that the oral health of mothers is a potentially important risk factor for the development of early childhood dental caries. Public health planners should consider this information when planning interventions in order to prevent the occurrence of early dental caries.