Objective: Early Childhood Caries (ECC) has been common among preschoolers in Sri Lanka over decades. A broad spectrum of determinants that act upon different levels is responsible for its development. Therefore, the relationships among these determinants should be studied extensively to control ECC. Design: Descriptive cross-sectional study with multistage cluster sampling. Setting: Registered preschools in Gampaha District. Participants: A total of 1038 three to four-year-olds and their mothers. Main outcome measures: Direct, indirect, and total effects of the determinants of ECC in structural equation models. Results: Sweet consumption had direct effects from permissive parenting (β=0.26, p=0.00) and the sweet consumption behaviour of the family (β=0.17, p=0.01). Oral hygiene behaviours had direct effects from permissive parenting (β=-0.46, p=0.00) and maternal oral health related self-efficacy (β=0.23, p=0.00). The dental attendance pattern had total effects from knowledge (β=0.18, p=0.00) and permissive parenting (β=-0.16, p=0.00). Conclusions: Parenting style, family sweet consumption behaviour and maternal oral health related self-efficacy were the most influential second-line determinants that affected oral health behaviours: sweet consumption, oral hygiene, and dental attendance pattern for the development of ECC. Keywords: dental caries, preschool children, structural equation modelling