Obesity is considered the disease of the era. It affects, not only adults but, also a large portion of the pediatric population. Proper optimization of the radiological procedures in obese children is a crucial step for adequate radiological imaging, and for assessment of obesity. The most common mean of defining obesity is the Body Mass Index (BMI), however, more precise methods are still needed and many radiological techniques can be of use. Radiology also plays an important role in the postoperative assessment of bariatric surgeries.