Bariatric surgery has considerably developed during the last 20 years in Belgium. The increase of prevalence of the morbid obesity and the development of multiple surgical procedures widened the spectrum of treatment. If a rigorous selection and a multidisciplinary approach of the patients are inescapable, the various decision-making algorithms plunge the practitioner into a certain confusion. The purpose of this paper is to clarify the advantages and the inconveniences of the different surgical treatments in light of the evolution of the principles and the objective results of the literature. Among the techniques proven and validated in the long run, one can mention the Silastic Ring Vertical Gastroplasty according to Mac Lean by minilaparotomy, the laparoscopic adjustable ring and the more recent gastric by pass. The evaluation of laparoscopic sleeve gastrectomy, and of duodenal switch is on course. The bilio-pancreatic by-pass according to Scopinaro remains strongly controversed. A meta-analysis of the literature confirms the success of the gastric bypass. Regarding to the long term follow-up, the adjustable gastric banding deceives. The sleeve gastrectomy should be analyzed in the long term. The preliminary results of a epidemiologic and financial study within a private hospital of Brussels reveals that the cost effective ratio is in favor the Silastic Ring Vertical Gastroplasty and the laparoscopic adjustable banding, as well in terms of public health support than the charge for the private insurance and the patient. The projection beyond 5 years reverses the tendency to plead in favor of the gastric by-pass. First with the hit-parade of comfort, food diversification, tolerance, gastro-esophageal reflux, and undoubtedly of the rate of recurrence, it supplants the others techniques for sweet eaters. The volume eaters can profit from a sleeve gastrectomy which undoubtedly supplants the Silastic Ring Vertical Gastroplasty responsible for late annular stenoses and reccurences.