Obesity and obesity related-diabetes are accepted as an important public health issue in the world. On the basis of etiology, obesity is subdivided into two groups as exogenous and endogenous. Exogenous obesity is usually result of increased high fat and high caloric food consumption and decreased physical activity. Whereas endogenous obesity may be emerged from causes as endocrinopaties, monogenic syndromes and other genetic syndromes. Measurement of body mass index should be a part of all health-related visits of children, as well as of school health programs. Regardless of etiology, all patients should be assessed for modifiable lifestyle risk factors and potential complications of obesity. Although prevention remains the best ap-proach to halt childhood obesity, management of obese children is important issue for pediatricians.