Surgical therapy to help the severely overweight has been performed for the past 40 years. As with every therapeutic modality, there have been changes, refinements and improvement as this therapy has evolved. Although the basic concept of gastric bypass remains intact, numerous variations are being performed at this time. Recent data compiled by the International Bariatric Surgery Registry have demonstrated that surgeons are moving from simple gastroplasty procedures, favouring the more complex gastric bypass procedures as the surgical treatment of choice for the morbidly obese patient. This review will discuss the evolution of the gastric bypass procedures, and the reasons for and results of the changes. Gastric bypass may represent the best surgical approach for the treatment of morbid obesity.