This study conducted a meta-analysis on the outcome indicator of body mass index from published school-based childhood obesity interventions done in the United States and the United Kingdom between 2000 and 2007. Electronic databases were searched for school-based childhood obesity interventions and a total of five studies were analyzed. The results of the pooled estimate of reviewed studies were not significant for the outcome measure body mass index at p < 0.05 level for fixed (effect estimate -0.0649 (95% CI: -0.29, 0.16)) as well as random effects (effect estimate 0.179 (95% CI: -0.38, 0.72)) models. In conclusion, it can be said that current school-based childhood obesity interventions do not seem to modify body mass index.