The prevalence of childhood and adolescent obesity has tripled in the past three decades. This increase has been accompanied by a dramatic rise in obesity-related health complications among American youth. Thus, many obese youth are now experiencing illnesses that will threaten their life expectancy in the absence of significant weight loss. Despite these concerns, a relatively modest body of research has focused on the treatment of adolescent obesity. Results from trials investigating the efficacy of behavioral and pharmacological treatments, like studies of these interventions with adults, suggest that individuals typically lose 5-10% of their initial weight. Unfortunately, weight regain is common. Given the increase in the number of obese adolescents, coupled with the modest results from more conservative treatment approaches, it is not surprising that bariatric surgery for adolescents who suffer from extreme obesity has grown in popularity. The weight losses after surgery are impressive and many adolescents, like adults, experience significant improvements in their physical and mental health postoperatively. However, only a small fraction of adolescents and adults who are heavy enough for bariatric surgery present for surgical treatment. Among those who undergo surgery, a significant minority appear to struggle with a number of behavioral and psychosocial issues that threaten their lifelong success. With all of this in mind, the current obesity problem in the United States and other Westernized countries likely will present a significant challenge to both current and future medical and mental health professionals who work with adolescents and young adults.