Overweight in childhood and adolescence is an important public health issue because of its rapidly increasing prevalence and associated adverse medical and social consequences. Recent studies have estimated that 15 percent of children in the United States are at risk for overweight, and an additional 15 percent are overweight. Important predictors of overweight include age, sex, race/ethnicity, and parental weight status. Generally, school-based prevention programs are not successful in reducing the prevalence of obesity. Treatment interventions include behavioral therapy, reduction in sedentary behavior, and nutrition and physical activity education. These interventions are moderately successful but may not be generalized to the primary care setting. Family physicians should focus on identifying at-risk and overweight children and adolescents at an early stage and educating families about the health consequences of being overweight. Interventions should be tailored to the patient and involve the entire family.