Cognitive-behavior therapy (CBT) is based on the notion that thoughts, emotions, and actions are reciprocally linked and that changes in one of these necessarily will produce changes in the others. In CBT, thoughts, emotions, perceptions, and information processing styles all play a key role in the development and remediation of behavior and adjustment difficulties of children with emotional and behavioral disorders. This article focuses on methodological issues involved in the development, implementation, and evaluation of outcomes in CBT. Several meta-analyses of the literature suggest that approximately 65% of children and youth receiving CBT improve compared to only 35% of controls. Criteria for evidence-based interventions used to determine the efficacy and effectiveness of cognitive-behavioral treatments are described. This article discusses the role of cognition in CBT, criteria for determining clinical significance of treatment effects, mediators and moderators of treatment outcomes, and treatment integrity of CBT.