In this randomized study, children and adolescents with primary diagnoses of separation anxiety or generalized anxiety disorders or social phobia received cognitive behavioral therapy, sertraline, a combination of these treatments, or placebo for 12 weeks. The results indicate that both cognitive behavioral therapy and sertraline reduced the severity of anxiety in children with anxiety disorders, and a combination of the two therapies had superior response rates. The results of this study indicate that both cognitive behavioral therapy and sertraline reduced the severity of anxiety in children with anxiety disorders, and a combination of the two therapies had superior response rates. Anxiety disorders are common in children and cause substantial impairment in school, in family relationships, and in social functioning. 1 , 2 Such disorders also predict adult anxiety disorders and major depression. 3 – 6 Despite a high prevalence (10 to 20% 3 , 7 , 8 ) and substantial morbidity, anxiety disorders in childhood remain underrecognized and undertreated. 1 , 9 An improvement in outcomes for children with anxiety disorders would have important public health implications. In clinical trials, separation and generalized anxiety disorders and social phobia are often grouped together because of the high degree of overlap in symptoms and the distinction from other anxiety disorders (e.g., . . .