The term metabolic surgery describes bariatric surgical procedures used primarily to treat type 2 diabetes and related metabolic conditions. Originally, bariatric surgery was used as an alternative weight-loss therapy for patients with severe obesity, but clinical data revealed its metabolic benefits in patients with type 2 diabetes. Metabolic surgery is more effective than lifestyle or medical management in achieving glycemic control, sustained weight loss, and reducing diabetes comorbidities. Perioperative adverse events are similar to other gastrointestinal surgeries. New guidelines for type 2 diabetes expand use of metabolic surgery to patients with a lower body mass index.