The prevalence of child and adolescent overweight and obesity is rapidly increasing and is associated with morbidity, both medical and psychosocial. Obesity is unlikely to resolve spontaneously. It is important that health professionals can assess obesity and initiate an action plan. The evidence base for what works best in the management of child and adolescent overweight and obesity is limited. It is uncertain whether protocols from clinical research trials can be translated into primary care. Dietary change, with an emphasis on lower fat intake and smaller portion size, should be commenced. There should be an increase in physical activity and a decrease in sedentary behaviours, combined with behavioural change and parental involvement. These are the elements of a lifestyle intervention. In the severely obese adolescent with obesity-related co-morbidity, the use of very low-energy diets and anti-obesity agents could be considered. Bariatric surgery may be indicated in carefully selected, older, severely obese adolescents.