The primary purpose of this study is to analyse the costs related to childhood obesity (CO) with reference to different models of healthcare systems. A systematic review of the economic impact of CO on healthcare systems was conducted by searching the main electronic scientific databases. Cost-of-illness (COI) analyses of children aged under 18 years who had been diagnosed as overweight or obese published up to July 2010 were considered. Short- and long-term consequences of CO were taken into account. In order to appraise the quality of the included studies, the British Medical Journal referees' checklist was used. About 3,844 COI analyses were initially found and 10 were finally considered in the current review: two studies referred to Beveridge and eight referred to Voluntary health insurance models. No studies have been conducted within a Bismarck model. Six studies considered in-patient costs, four studies estimated outpatient and primary care costs and seven studies considered pharmaceutical costs. The average quality of the included analyses was medium. The analysis confirmed the significance of CO related costs and the heterogeneity among available studies, which made it impossible to compare the different healthcare models.