Increasing attention is being focused on potential risk factors that may lead to overweight in children and adolescents and that may, therefore, be important targets for intervention. Historically, children's eating and activity habits have received considerable attention in programmatic research targeted at prevention and treatment of overweight. However, more recent research has found that additional factors may play a role in this growing epidemic. Of particular interest is children's sleep duration. The goal of this article is to review research that has assessed the association between children's sleep duration and overweight risk in an attempt to uncover the potential role of sleep in the growing obesity epidemic. Although shortened sleep duration is associated with increased overweight in children, additional research is needed prior to recommending that children's sleep be increased as a means to address the current obesity epidemic.