Objective: To study the correlation between flatfoot and joint laxity in healthy children. Methods: We evaluated 328 children with ages between 3 to 15 years, with no previous musculoskeletal complaints. We classified them by the presence of joint laxity according to the Beighton and Horan criteria, and by the presence of flatfoot according to the Valenti classification. The data obtained werecorrelated with gender, age, ethnic group, and dominant side. Fisher's exact test and chi-square test were applied to analyze theresults. Results: A percentage of 83.9% ofindividuals with joint laxity was observed in children younger than 7 years of age (p < 0.001*). There is a significant association between joint laxity and gender (p = 0.025*), as girlsexhibited a greater percentage of laxity (51.02%). We observed a significant association between joint laxity and type of foot (p =0.003*), since the flatfooted group presented a higher percentage of laxity (54.96%). Flatfoot was also associated to joint laxity when we considered only the males (p = 0.001*), which was not observed in the females group. Conclusion: In the population studied, joint laxity was more frequently observed in children younger than 7 years of age, in females, and in individuals with flatfoot. There was no association between joint laxity and ethnic group or dominant side.