Families are recommended as the agents of change for weight loss in overweight and obese children; family approaches are more effective than those that focus on the child alone. However, interventions that focus on parents alone have not been summarized. The objective of this review was to assess the effectiveness of interventions that compared a parent-only (PO) condition with a parent-child (PC) condition. Four trials using a similar between-group background approaches to overweight and obese children's weight loss met the inclusion criteria, but only one trial reported sufficient data for meta-analysis. Further information was obtained from authors. Meta-analysis showed no significant difference in z-BMI from baseline to end of treatment between the conditions (three trials) or to end of follow up (two trials). The trials were at risk of bias and no single trial was at lower risk of bias than others. There is an absence of high quality evidence regarding the effect of parent-only interventions for weight loss in children compared to parent-child interventions, but current evidence suggests the need for further investigation.