Anxiety disorders and related problems affect a large number of children and adolescents, are impairing, and can affect long-term functioning if left untreated. Cognitive behavioral therapy (CBT) is an efficacious treatment approach that teaches anxious youth multiple skills to help manage anxiety symptoms, challenge unrealistic assumptions, and approach frightening situations. This chapter describes and illustrates CBT strategies and principles in the context of anxious children and adolescents. Worksheet templates and case illustrations are provided to demonstrate how a clinician turns principles into practice using a flexible, principles-based approach. The principles and concrete tools provided herein are designed to help practitioners meet the specific needs of their clients, representing a diversity of clinical profiles and settings.