Childhood obesity is a serious and increasing threat to public health. The prevalence of overweight and obesity among children is increasing not only in the United States, but worldwide. Lack of physical activity and poor dietary intake are primary reasons for the positive energy balance that results in overweight and obesity among children and adults. Evaluations of interventions in school aged children have not been found to be generally successful and it is now time for the public health community to turn their attentions to an earlier point in the life course development, namely preschool. Studies have demonstrated the increased need for early intervention as greater numbers of children are found to have precursors to chronic illness conditions such as diabetes, metabolic syndrome, cardiovascular disease and high blood pressure. This coupled with increasing numbers of states moving towards universal preschool (or pre-kindergarten), the setting of the school will prove to be an important point of early intervention for children's health and well-being. Physical activity engagement among children has been found to be decreasing over time, concurrently, the amount of time children spend in front of a television or computer has been found to be increasing, especially among minority and low income youth. However, the use of video game technology to motivate and engage children to be physically active, exergaming, is increasing in popularity and has shown potential to positively affect school aged children's physical activity. The proposed collaborative team at the George Washington University (GWU) is in an excellent position to evaluate the use of exergaming to encourage recommended levels of physical activity among preschoolers. Utilizing research perspectives from several social science, education and exercise science disciplines, and a study design adapted from validated program planning and evaluation models, we propose to build upon findings from the preliminary work conducted by our team and others. Consistent with the goals and mission of the NIDDK of the National Institutes of Health and Healthy People 2020, we propose to conduct a randomized experimental efficacy trial with 150-180 low income minority preschoolers in Washington DC to examine the effects of exergaming compared to typical structured games and activities on preschoolers' enjoyment and energy expenditure among a selected sample of preschoolers ages 3 to 5. This study has the potential to impact the field by providing needed data on an innovative intervention that would be inexpensive and easy to replicate in many preschool settings. Our findings will lead us to a larger R01 application and provide a clear understanding of the early intervention of exergaming to encourage physical activity among underrepresented preschoolers in the short term and decrease overweight and chronic health conditions such as diabetes and metabolic syndrome in the long term.