The ultimate goals of assessment in overweight youth are to guide treatment targets, identify optimal treatment interventions, and help provide a better understanding of the role that behavior and psychosocial factors may play in this condition. This chapter focuses on interviewing strategies and psychometric measures for the behavioral, psychological, and psychosocial assessment of overweight children. Behavioral assessment of obesity in adults relies primarily on interviewing the patient in conjunction with self-report instruments and self-monitoring (Phelan & Wadden, 2004). This method also is appropriate for pediatric populations, although the inclusion of parents or primary caregivers in interviewing, self-report assessment, and monitoring is key for both children and adolescents.It is useful to clarify in which settings and for which type of professionals the various elements of assessment apply. We base our discussion in this chapter on a comprehensive assessment to be made by a mental health professional on a patient presenting for weight loss treatment in a specialty clinic. In many cases, it is also recommended that the mental health professional collaborate with other professionals (e.g., physicians, dieticians, exercise physiologists) to ensure the best assessment and treatment of the patient. Overweight patients may present with psychological problems, behavioral problems, school 137