OBJECTIVE:To conduct a meta-analysis to examine the effectiveness of active video games (AVGs) interventions on motor function in people with developmental disabilities. DATA SOURCES:An electronic search of 7 databases (PubMed, EbscoHost, Informit, Scopus, ScienceDirect, Proquest, PsychInfo) was conducted for randomized controlled trials (RCTs) evaluating AVGs to improve motor function in people with developmental disability, published through to May 2018. STUDY SELECTION:Only articles in a peer-reviewed journal in English were selected and screened by 2 independent reviewers for RCTs that compared AVGs to conventional therapy. Twelve RCTs involving 370 people with developmental disabilities met the inclusion criteria for quantitative analysis. DATA EXTRACTION:Two independent reviewers assessed risk of bias and study quality using the Egger's R, grading of recommendation, assessment, development and evaluation, and Template for Intervention Description and Replication checklists. DATA SYNTHESIS:Three meta-analyses revealed a large effect size for AVGs to improve gross motor skills (Hedges' g=0.833, 95% confidence interval [95% CI]=0.247-1.420), small to medium effects for balance (g=0.458, 95% CI=0.023-0.948), and a small, nonsignificant effect for functional mobility (g=0.425, 95% CI= -0.03 to 0.881). Training frequency (ie, number of sessions per week) moderated the effect of AVGs on motor function in people with developmental disabilities. CONCLUSION:We conclude that AVGs show task-specific effectiveness for gross motor skills but the effects are moderated by training intensity. However, because of the low number of trials, diverse diagnoses, variable dosage, and multiple outcome measures of the included trials, these results need to be interpreted with caution.