This article reviews the empirical research literature on behavioral assessment and intervention methods in the context of diabetes mellitus in children and adolescents. The review summarizes the pathophysiology, medical management, and monitoring of pediatric type 1 and type 2 diabetes. Next, the article describes common behavioral barriers to acceptable diabetes management and adequate metabolic control and the role of behavior change agents in evaluation and intervention for these problems. Validated approaches to the assessment of diabetes-specific behavioral problems are described for the measurement of treatment adherence, diabetes-related fears and avoidance behaviors, diabetes-specific social skills, and disease-related stressors. Behavioral interventions that have empirical support are discussed, including treatments that target treatment adherence, social skills, coping skills, family communication and problem solving, anxiety and stress management, and weight control. The article concludes with clinical practice recommendations for behavior change specialists who have the opportunity to work with this population.