Objectives: To compare the motor competence of overweight/obese preschoolers with eutrophic peers with a similar level of physical activity, sex, age, socioeconomic status, maternal education, quality of the home environment and quality of the school environment, and to verify the association of body fat mass with gross motor skills in preschoolers.Design: Quantitative, exploratory, cross-sectional study design.Methods: Forty-nine children, aged 3 to 5 years old, from public schools in a Brazilian city were classified into eutrophic and overweight/obese groups.Results: Overweight/obese preschoolers had worse Locomotor subtest standard scores than their eutrophic peers (p = 0.01), but similar skills, Object Control subtest scores and Gross Motor Quotient (p > 0.05). Excess body fat mass explained 13% of the low Locomotor subtest standard scores in preschoolers (R2 = 0.13; p = 0.007).Conclusion: Excess body fat mass is associated with worse locomotor performance when the model is adjusted for contextual factors such as level of physical activity, sex, age, socioeconomic status, maternal education, quality of the home environment and quality of the school environment. Thus, excess body fat mass partly explains lower locomotor skills in preschoolers. These findings may assist with the development of public guidelines aimed at child health in order to outline strategies that enable the stimulation of locomotor skills in preschoolers with excess body fat mass.