BACKGROUND AND AIM: Early loss of deciduous teeth has negative effects on chewing function, aesthetics, self-esteem, and permanent dentition. This study aimed to evaluate the prevalence of premature primary tooth loss and the contributing factors in children aged 36-71 months in Babol City, north of Iran. METHODS: In this cross-sectional study, 558 healthy preschool children underwent oral examination to record the type and frequency of premature tooth loss and Silness-Loe plaque index. The parents were then asked to fill out a questionnaire about the related factors. Data were evaluated by SPSS software and analyzed using one-way analysis of variance (ANOVA), independent samples t-test, and multiple linear regression analysis. The level of significance was set at P ≤,0. 05. RESULTS: The frequency rate of missing primary teeth was 1. 56% estimated in 13. 62% of children. The mean number of missing teeth showed a significant difference among different subgroups of children classified based on parent’, s education (P = 0. 001), socio-economic status (P = 0. 001), child's age (P = 0. 020), plaque index (P = 0. 001), frequency of consumption of cariogenic snacks (P = 0. 001), and brushing (P = 0. 001). According to multiple linear regression test, father's educational level, socio-economic status, plaque index, and frequency of consumption of cariogenic snacks were correlated with the number of missing teeth. CONCLUSION: Less than one-seventh of children had at least one premature missing primary tooth. Child's age, parent’, s educational level, socio-economic status, frequency of consumption of cariogenic snacks, plaque index, and brushing are related to premature primary tooth loss.