Objective: The purpose of this study was to examine the effect of active videogames (AVGs) on underserved minority children's on-task classroom behavior, academic effort, and fitness. Materials and Methods: A one group pre- and posttest repeated measures design was used. In Fall 2013, 95 fourth grade children (57 boys, 38 girls; 96% of minority) from three classes at an underserved urban elementary school participated in teacher-supervised AVG activities (e.g., Wii Sports, Xbox Just Dance). Specifically, students participated in a 50-minute weekly AVG program at school for 6 weeks. Children's academic effort was evaluated by classroom teachers using a validated scale that assessed activity, attention, conduct, and social/emotional behavior. Moreover, children's classroom behavior was observed immediately before and after each AVG session by trained researchers. Finally, cardiovascular fitness was also measured. Results: A paired t-test was used to assess teacher-rated student effort, while one-way (gender) analysis of variance (ANOVA) with repeated measures was performed to analyze children's on-task classroom behavior. There was a significant effect on children's effort between the first (mean = 3.24, SD = 0.75) and last week (mean = 3.41, SD = 0.73) assessments, t = 2.42, P = 0.02. In addition, there was a significant effect on classroom behavior, F = 33.103, P < 0.01. In detail, children scored significantly higher on on-task behavior during the post-AVG observation (mean = 81.4, SD = 12.3) than seen during the pre-AVG observation (mean = 69.8, SD = 14.9). However, no main effect was indicated for gender, F = 0.39, P = 0.54. No significant improvement in cardiovascular fitness was observed, although slight improvements were seen. Conclusion: Offering an AVG program at school could improve underserved minority children's classroom on-task behavior and academic effort. Future studies may include a control group to further confirm the effectiveness of AVG activities. Practical implications for educators and other stakeholders are provided.