Controversy persists regarding the utility of school-based interventions for obesity prevention and control and for related health promotion. This article reviews the pertinent evidence, based partly on a recent systematic review and meta-analysis by the author and colleagues. Of 64 relevant papers, 21 papers representing 19 distinct studies met quality criteria; half of these were published since 2000. Despite marked variation in measures, methods, and populations that handicap interpretation of this literature, evidence clearly demonstrated that school-based interventions had significant effects on weight. Thus available research evidence does present a case for school-based interventions. Despite the fact that such evidence is limited to date, the urgency of the obesity and diabetes epidemics cries out for action. Intervention is warranted on the basis of both extant evidence and common sense, with methodologically robust evaluation concomitantly to test our assumptions and verify our intuition.