The prevalence of childhood obesity is rising, and pediatric obesity has become an important public health issue. It can be defined as BMI more than 95th percentile for age and sex, whereas overweight is defined as BMI more than 85th percentile. Using these cut points, more than one quarter of all children and adolescents are either overweight or obese. The recent increases in the prevalence of childhood obesity result from the interaction between a strong genetic predisposition that facilitates storage of fat, easy access to calorically dense foods, and the low levels of physical activity that characterize modern societies. Childhood obesity has pervasive psychosocial and medical consequences in the short term and the long term. Many of these consequences may not be apparent for decades, but the metabolic complications of obesity and the insidious effects of early psychosocial stigmatization are sometimes observed even in young children. For pediatric obesity, behavioral approaches seem moderately efficacious in younger children. Comprehensive programs generally include modification of dietary and activity habits and some degree of parental involvement. Medication for pediatric obesity cannot be recommended currently outside the context of clinical trials. Gastric bypass surgery is effective but should be considered a last resort for the child with life-threatening complications of obesity.