Objectives: This study adopted an intergenerational approach, aiming to answer the following research questions: (a) Are maternal oral health‐related behaviours and oral health associated with dental caries in preschool children?; (b) Do maternal caregiving behaviours mediate the association between maternal oral health‐related behaviours and dental caries in preschool children. Methods: Children aged 5 years, enrolled in the 2004 Pelotas (Brazil) Birth Cohort, were investigated (n = 1303). Children were dentally examined using WHO criteria to assess the number of decayed, missing and filled surfaces (dmfs), and their mothers were interviewed. Standardized direct, indirect and total effects of maternal characteristics (frequency of toothbrushing, dental anxiety, the pattern of dental attendance, self‐perception about oral health and self‐reported dental caries) on maternal caregiving behaviours and children's dmfs were assessed using path analysis. Results: Mean dmfs was 4.1 (95% CI 3.6;4.5). Maternal oral health‐related behaviours had no direct effect on children's dental caries: child dental attendance pattern partially mediates the effect of maternal dental attendance pattern on dental caries (87.8%; P < 0.05) and partially mediates the effect of maternal dental anxiety (39.9%; P < 0.001). Child frequency of toothbrushing mediates 28.0% (P < 0.001) of the effect of maternal frequency of toothbrushing on dental caries. Conclusions: Socioeconomic factors directly influenced children's caries experience, whereas maternal oral health‐related behaviours had no direct effect. It was observed an indirect effect of maternal dental anxiety and dental attendance pattern on children's dental caries mediated by caregiving behaviours, such as child dental attendance pattern and frequency of toothbrushing.