Abstract: Objective To analyze the prevalence of dental caries and its influencing factors among preschool children aged 3-5 years old in Pudong New Area of Shanghai, and to provide evidence for developing caries prevention strategies for this population. Methods A cross-sectional design was adopted. Using multistage cluster random sampling, 1,195 children aged 3-5 years old were selected from 9 kindergartens in Pudong New Area of Shanghai from October to December 2023 for on-site oral examinations and questionnaire surveys. A multivariate logistic regression model was used to analyze factors associated with early childhood caries (ECC). Results A total of 1,083 participants were included, with a caries prevalence of 39.06%. Multivariate logistic regression analyses showed that, compared with children who were aged 3 years old, used fluoride toothpaste, consumed carbonated beverages less than once per week, and ate after nighttime tooth brushing less than once per week, those who were aged 5 years old (OR = 2.199, 95% CI: 1.433-3.374, P < 0.001), aged 4 years old (OR = 1.800, 95% CI: 1.346-2.407, P < 0.001), did not use fluoride toothpaste (OR = 2.334, 95% CI: 1.749-3.116, P < 0.001), consumed carbonated beverages ≥1 time per week (OR = 1.591, 95% CI: 1.157-2.188, P = 0.004), and ate after nighttime tooth brushing ≥1 time per week (OR = 1.571, 95% CI: 1.129-2.184, P = 0.007) were at a higher risk of dental caries. Compared with children who were exclusively breastfed, those with mixed feeding (half breastfeeding and half formula feeding) had a lower risk of caries (OR = 0.554, 95% CI: 0.368-0.836, P = 0.005). Conclusion In 2023, the caries prevalence among preschool children aged 3-5 years old in Pudong New Area still lagged behind advanced international levels. Age, feeding pattern within the first 6 months of life, use of fluoride toothpaste, frequency of carbonated beverage consumption, and eating after nighttime tooth brushing were all associated with childhood caries. It is recommended to implement targeted health education in kindergartens, strengthen behavioral guidance for caregivers, and effectively safeguard the oral health of preschool children.