Obsessive-compulsive disorder is recognized to be a relatively common disorder in childhood and adolescence. While the cognitive behavioral model of OCD has received considerable empirical support from adult studies, there has been relatively little investigation of this model in childhood populations. In this paper, the definition of OCD in children and ad- olescents and the epidemiological investigations are explored. Then the paper reviews the cognitive--behavioral theory and provides empirical support for the theory of OCD in child and adolescent samples. Finally, the paper concludes by ma...