Cognitive behavioral therapy (CBT) is perhaps one of the most frequently used psychotherapeutic orientations, with considerable research supporting its effectiveness and adaptability in clinical practice. As the name implies, CBT integrates the rationale and techniques from both cognitive therapy and behavioral therapy, taking advantage of their complimentary relationship. For example, as cognitive therapy seeks to change behavior by challenging maladaptive thoughts, behavioral therapy employs more direct, yet complimentary methods, such as pairing reinforcing stimuli with a desired behavior or aversive stimuli with an undesired behavior. CBT aims to quickly resolve maladaptive thoughts or behaviors without necessarily delving too deeply into why they may occur. Thus, effective courses of therapy might be as short as a single session, or as long as a lifetime, depending on the specific needs of the individual. This report summarizes evidence gained from systematic reviews focusing on the efficacy of CBT in the treatment of depression and anxiety disorders.