This chapter discusses cognitive-behavioral therapy (CBT) as applicable to all eating disorders in adults and adolescents. It reviews the most recent manual-based enhanced CBT (CBT-E), which not only appears to be more effective than the previous protocol but also is applicable to all eating disorders and enhances individualizing treatment even within specific diagnoses. The chapter considers the effectiveness of CBT compared to behavior weight loss treatment, pharmacotherapy, and interpersonal psychotherapy (IPT). It considers patient access to evidence-based CBT and discusses effective dissemination and implementation of competently administered CBT-E as a research priority. It describes and considers the effectiveness of a guided self-help form of CBT (CBTgsh), which provides a brief, cost-effective, acceptable, and scalable intervention. It describes possible further development of CBTgsh as a scalable e-therapy (using Internet and mobile devices) given that it is a program-based intervention that can be widely implemented by nonspecialists.