Objective: To estimate the prevalence and associated factors of dental trauma in 6-year-old school children in the city of Palhoça, Brazil. Material and Methods: Cross-sectional study nested in a cohort study. It involved a representative sample of school children born in 2009, residing in the municipality and regularly enrolled in public and private schools (n = 1,102). Clinical data were obtained through oral exams. To evaluate the incisal overjet, the distance in millimeters was measured horizontally from the labial surface of the lower central incisor to the labial surface of the upper incisor. Bivariate analyses were performed using the Chi-square test, with a p-value <0.05 considered statistically significant. Multivariate analyses using Poisson Regression were performed to identify independent associations between the prevalence and the independent variables studied. Results: Prevalence of dental trauma was 4.2% (95% CI 3.0-5.4). Dental trauma was statistically associated with studying in a private school (PR = 1.03; 95% CI 1.01-1.06) (p=0.016) and with inadequate lip coverage (PR = 1.08; 95% CI 1.01-1.14) (p=0.016). Conclusion: The prevalence of 4.2% of dental trauma in six-year-old children, associated with inadequate and greater lip coverage in children from private schools should be taken into account, since most teeth at this stage are newly erupted.