To report the findings of a systematic review of family-based psychosocial interventions with pediatric oncology populations.A number of intervention studies documenting psychosocial interventions for childhood cancer populations, that incorporated multiple family members, were examined.Twenty-one studies were identified that met the criteria for inclusion and provided the data necessary for synthesizing the results. Findings illustrate that multiple family members are integrated into interventions for childhood cancer in a number of ways. Considerable variation was observed regarding the family member combinations targeted and the intervention modalities employed. A minority of interventions met the criteria for empirically validated treatments; however, evidence of beneficial outcomes was observed across the majority of interventions reviewed.Findings suggest the feasibility, acceptability, and potential effectiveness of family-based psychosocial interventions in pediatric oncology. Recommendations for conducting future intervention studies are provided including the integration of qualitative methods in evaluations of family-based interventions.