The study aims to observe the effect of moderate intensity exergaming on mastering of fundamental movement skill and reduction in body mass index (BMI) in overweight and obese children in Surabaya, Indonesia. The participants were 17 primary school students, aged 6-12 years. All participants had a BMI above percentile 85 (overweight and obese) and performed 12 sets of moderate intensity exergaming for four weeks, 3x/week, 30-40 minutes/session. The variables were fundamental movement skill, body weight, BMI, body fat percentage, and prediction energy expenditure. They were taken 3 days prior first exercise (pre-test) and after last exercise (post-test) except for energy expenditure. Prediction of energy expenditure were taken in first and last of exergaming session. The result showed, there was improvement in component jumping of fundamental movement skill, but not in others component. There were also significant decline on body weight, BMI, and body fat percentage, but not in energy expenditure. The conclusion of this research is the regular moderate intensity exergaming for 4 weeks can help children to improve their fundamental movement skill and reduce BMI.