A growing body of research supports the efficacy of cognitive-behavioral therapy (CBT) for adolescent depression. The mechanisms through which CBT exerts its beneficial effects on adolescent patients suffering from depression, however, remain unclear. The current article reviews the CBT for adolescent depression process literature. Our review focuses on several process variables: the therapeutic alliance, patient cognitive change, and therapist adherence to, and competence in, the theory-specified techniques of therapy. Given that the vast majority of CBT process research has been conducted in the context of adult psychotherapy, we also review relevant adult research as a framework for understanding adolescent process research and to inform future investigations. Methodological issues are addressed and recommendations for future process research are raised.