Early childhood caries (ECC) is a worldwide public health problem. The biological and behavioural determinants that are directly involved in ECC have been well documented; however, evidence on the effects of some psychosocial factors remains conflicting. This study aimed to assess the association between child temperament and ECC in Chilean preschoolers. Prior approval of the protocol was obtained from the ethics committee of Universidad de La Frontera (Folio N° 020_17), and all of those involved in the study provided signed informed consent forms. The cross-sectional study was conducted with 172 children aged 3 to 5 years attending preschools in Temuco, Chile. Each child’s temperament was assessed based on parents’ responses to the Early Childhood Behaviour Questionnaire. The outcomes assessed were caries prevalence and caries experience (dmft scores). The covariates included were socioeconomic position, cariogenic diet, prolonged breastfeeding, presence of dental plaque and hypoplasia. Logistic regression models were used to predict caries prevalence and negative binomial regression for caries experience. The prevalence of ECC was 29.1%, and the most frequent child temperament was ‘effortful control’. Regression model analyses, adjusting for covariates, showed no evidence of an association between any domain of children’s temperament (surgency, negative affect and effortful control) with the prevalence of caries or caries experience. This cross-sectional study found no association between childhood temperament and ECC in preschool children for this population. However, due to the specificity of this population, the association cannot be entirely ruled out. Further studies are needed to help understand the association between temperament and oral health, including the influences of family environment factors and culture.