Obesity has become a big problem in Japan as in Europe and United States. Principle of the treatment of obesity is diet and exercise therapy, but these treatments are often failed. Pharmacotherapy is now second choice, but is expected great developments by recent advances of molecular biology of obesity. Appetite suppressants were previously applied for clinical use and showed a certain effect to decrease body weight. In Japan, only madindol is available and sibutramine is one the clinical trial. In the medical treatment of obesity including pharmacotherapy, we have to select the obese patients who should be under the medical control, and we should not only reduce the body weight, but medicate the complications of obesity.