Morbid obesity is recognized as a serious health problem. The costs associated with obesity are substantial; billions of dollars are spent yearly in the United States on weight reduction, and a goodly portion of that is for treatment of the many complications associated with obesity. In 1991, the second National Institutes of Health Consensus Conference, after reviewing all data, concluded that surgical therapy should be offered to severely obese patients unresponsive to medical therapy. Since that time, the surgical community has settled on the Roux-en-Y gastric bypass, usually performed laparoscopically, and the adjustable gastric banding procedure as the means of accomplishing weight reduction with the fewest complications. We hope that this theme issue will alert you to the principles and pitfalls of bariatric surgery and the newer, and perhaps more physiologic, endocrine approaches to this universal problem.