Technical Abstract: Parents are often involved in interventions to engage youth in physical activity, but it is not clear which methods for involving parents are effective. A systematic review was conducted of interventions with physical activity and parental components among healthy youth to identify how best to involve parents in physical activity interventions for children. Identified intervention studies were reviewed in 2008 for study design, description of family components, and physical activity outcomes. The quality of reporting was assessed using the CONSORT checklist for reporting on trials of nonpharmacologic treatments. The literature search identified 1227 articles, 35 of which met review criteria. Five of the 14 RCTs met > or =70% of CONSORT checklist items. Five general procedures for involving parents were identified: (1) face-to-face educational programs or parent training, (2) family participatory exercise programs, (3) telephone communication, (4) organized activities, and (5) educational materials sent home. Lack of uniformity in reporting trials, multiple pilot studies, and varied measurements of physical activity outcomes prohibited systematic conclusions. Interventions with educational or training programs during family visits or via telephone communication with parents appear to offer some promise. There is little evidence for effectiveness of family involvement methods in programs for promoting physical activity in children, because of the heterogeneity of study design, study quality, and outcome measures used. There is a need to build an evidence base of more-predictive models of child physical activity that include parent and child mediating variables and procedures that can effect changes in these variables for future family-based physical activity interventions.