Obesity is defined as morbid when the Body Mass Index (BMI) exceeds 40 kg/m(2). The initial approach should be a multidisciplinary medical assessment. The three principal surgical interventions practiced in France are: placement of an adjustable gastroplasty ring, vertical banded gastroplasty, and Roux-en-Y gastric bypass (short circuit). The indications for surgical therapy are those defined by recent consensus conferences: Morbid Obesity (BMI 40), Major Obesity (BMI 35) with associated factors of co-morbidity, or stable or worsening obesity of five years duration resistant to multidisciplinary medical management for a least a year. Studies of these three surgical techniques with at least one year of follow-up shows significant average weight loss on the order of 20-50 kg. Studies of adjustable ring gastroplasty show an average loss of 45% of excess weight at one year; maintenance of weight loss beyond one year is not yet well documented. Long term results of vertical banded gastroplasty and gastric bypass are better defined. Initial weight loss for vertical banded gastroplasty is about 61%; some patients maintain this weight loss and others tend to regain some of their excess weight. For gastric bypass, the initial weight loss is about 68% of excess weight and there is a greater tendency to maintain this weight loss. Comparative studies, mostly from North America and of variable methodologic quality, conclude that weight loss with gastric bypass is superior to that with vertical banded gastroplasty. The indications for the respective techniques vary according to the severity of the obesity (BMI), and to the patient's eating habits. Gastric bypass which has the best short and long term results may be best reserved for patients with the most severe obesity or co-morbid conditions.