Surgical treatment of obesity by methods that have withstood over 5 years of clinical evaluation is effective in ameliorating and even curing manifest serious co-morbid diseases such as diabetes, hypertension, and respiratory distress in the majority of patients. Despite numerous shortcomings and limitations, surgical methods are the only viable alternative for achieving and maintaining substantial weight loss in dangerously obese patients and, therefore, represent a legitimate, often life-saving, intervention. Nevertheless, the magnitude of weight loss varies widely, as does the number of patients lost to follow-up or requiring multiple operations. Safety of performing the surgery and recognition and successful treatment of side effects in cooperating patients has improved greatly over the past 10 years. More effort needs to be put into improving patient selection to allocate patients to specific types of operations and to identify those patients who may not require surgery.