Background: Few school settings offer opportunities for preschool children to engage in structured physical activity, and only a few studies have been conducted examining exergaming’s effectiveness on health outcomes in this age group. This study’s purpose, therefore, was to examine a school-based exergaming intervention’s effect on preschool children’s perceived competence(PC), motor skill competence(MSC), and physical activity versus usual care(recess), as well as to examine gender differences for these outcomes.Methods: A total of 65 preschool children from 2 underserved urban schools were assigned to 1 of 2 conditions, with the school as the experimental unit:(1) usual care recess group(8 weeks of 100 min of recess/week(5 days £ 20 min)) and(2) exergaming intervention group(8 weeks of100 min of exergaming/week(5 days £ 20 min) at school). All children underwent identical assessments of PC, MSC, and moderate-to-vigorous physical activity(MVPA) at baseline and at the end of the 8 th week.Results: A significant Group £ Time effect was observed for MVPA, F(1, 52) = 4.37, p = 0.04, h2 p= 0.04, but not for PC, F(1, 52) = 0.83, p = 0.37,h2 p= 0.02, or MSC, F(1, 52) = 0.02, p = 0.88, h2 p= 0.00. Specifically, the intervention children displayed significantly greater increased MVPA after8 weeks than the comparison children. Additionally, there was a significant time effect for MSC, F(1, 52) = 15.61, p < 0.01, h2 p= 0.23, and gender effect for MVPA, F(1, 52) = 5.06, p = 0.02, h2 p= 0.09. Although all preschoolers’ MSC improved across time, boys demonstrated greater MVPA than girls at both time points.Conclusion: Exergaming showed a positive effect in promoting preschool children’s MVPA at school and has the potential to enhance PC and MSC. More research with larger sample sizes and longer study durations are warranted.