Bariatric surgery has evolved considerably since the introduction of jejunoileal bypass in the 1950s. With modifications of early procedures, implementation of new techniques, and establishment of minimally invasive approaches, operative intervention has become the mainstay in the treatment of extreme (class III) obesity. The laparoscopic adjustable gastric band technique is the most common purely restrictive procedure. Advantages of the laparoscopic adjustable gastric band include reduced perioperative morbidity and mortality compared to other bariatric procedures, but this procedure has been associated with substantial intermediate and long-term complications. Although vertical banded gastroplasty was associated with decreased perioperative morbidity and acceptable early weight loss, results from long-term follow-up have been discouraging. Roux-en-Y gastric bypass (RYGB) is the most common bariatric procedure performed in the United States because of its effectiveness in long-term weight loss and low rates of serious complications. Modifications of RYGB to induce malabsorption have led to greater weight loss but increased risks of metabolic and nutritional sequelae. Duodenal switch is a malabsorptive procedure associated with excellent weight loss and resolution of weight-related comorbidities, but concerns regarding potential metabolic and nutritional sequelae have limited its widespread use. Laparoscopic approaches to bariatric procedures have reduced wound-related complications and improved patient recovery. However, the incidence of anastomotic leak and internal hernia is higher after laparoscopic RYGB compared to the open approach. Each of the currently available bariatric procedures has both advantages and disadvantages that must be considered in determining which operation should be selected for an individual patient.