Prevalence of pediatric obesity has increased worldwide in the last 20 years. Obese children suffer not only physical complications but also mental health problems such as depression, attention deficit hyperactivity disorder (ADHD), and eating disorders, as well as psychosocial impairments, such as school adjustment problems, bullying, and low self-esteem. Recently, there have been some studies on the association of mental health problems and pediatric obesity. In the treatment of pediatric obesity, many previous studies suggest multidisciplinary treatment. However, cognitive behavioral therapy (CBT) has attracted attention because obese children are accompanied by body image distortion, emotion dysregulation, and difficulties in stimulus control. This review is a narrative summary of the recent studies on mental health problems and CBT in pediatric obesity. The relationship between depression/ anxiety and pediatric obesity is still inconsistent but recent studies have revealed a bidirectional relation between depression and obesity. Additionally, some studies suggest that obese children may have eating disorder symptoms, like loss of control eating, and require therapeutic intervention for pediatric obesity treatment. Furthermore, impulsivity and inattention of ADHD symptom is thought to increase the risk of obesity. It has also been suggested that CBT can be very effective for mental health problems such as depression, impulsivity, and body image distortion, that may coexist with pediatric obesity, and use of multimedia and application can be useful in CBT.