Obesity is associated with an increased risk of developing insulin resistance and type 2 diabetes. Development of type 2 diabetes can be delayed or sometimes prevented from manifestation in individuals with obesity that are able to lose weight. Weight loss can be achieved either medically with behavioral therapies that combine diet and exercise treatment or with behavioral therapies combined with weight-loss medications or weight-loss surgery. There is strong evidence of an amelioration or resolution of type 2 diabetes in patients undergoing gastric bypass surgery. A recently published retrospective cohort study indicated that long-term total mortality from diabetes, heart disease, and cancer after gastric bypass surgery was substantially reduced. In this review, we summarize the evidence of surgical interventions in the treatment of type 2 diabetes.