Historically, psychiatric descriptions of childhood anxiety disorders date back to case reports in the early part of the twentieth century (e.g., Little Hans, Little Albert, Little Peter; see Beidel and Turner 2005). These descriptions, although differing in theoretical orientation, share a common theme—anxiety in children is not simply a "developmental phase." Rather, anxiety symptoms can be serious, distressful, and functionally impairing. Yet, despite their importance, the notion that children would outgrow their fears limited scientific investigation. Until the early 1990s, there were few randomized controlled trials (RCTs) addressing the pharmacological or psychological treatment of anxiety disorders in children. Since that time, there has been an explosion of interest in treatment, primarily from pharmacological and cognitive-behavioral perspectives. In this chapter, we review cognitive-behavioral treatment (CBT) for anxiety disorders.