A B S T R A C T ObjectiveTo analyze the incidence of overweight/obesity and associated factors in children aged six years or less during a two-year follow-up. MethodsThis longitudinal cohort study followed 242 preschoolers from Florianópolis, Santa Catarina, from 2008 to 2010. The outcome was overweight/obesity (Z-score >+2) measured by accumulated incidence. The Chi-square test measured the differences between the study factors. The association between overweight/obesity and associated factors was analyzed by adjusted and crude rate ratios. ResultsNine (4.00%) of the 222 non-overweight/obese children in 2008 were overweight/obese in 2010, indicating an accumulated incidence of overweight/obesity of 4.05% (1.4-6.7).