This review aims to assess the effectiveness of psychological interventions for treating childhood obesity. Firm conclusions about the effectiveness of psychological interventions to treat childhood obesity remain unclear. Based on current knowledge, the review suggests that a number of interventions may be effective including: multi-component family-based behavioural interventions, interventions aimed at reducing sedentary behaviour and/or increasing physical activity levels as a component of family-based behavioural treatments, in addition to population-based school-wide treatment for girls. Further investment is needed to improve current research and find new, more imaginative ways to research childhood obesity.