Diabetes mellitus type 2 is a chronic disease with increasing prevalence in western society. Obesity represents a well established risk factor for the development of diabetes mellitus type 2. Several studies on surgical procedures for the treatment of obesity have shown a postoperative reduction of obesity-related co-morbidities. Thus, diabetes mellitus type 2 was shown to resolve or improve in more than 75% of morbidly obese patients (BMI >35) after bariatric surgery. These insights paved the way for the advent of metabolic surgery - a novel field with the goal to improve glucose metabolism in patients with a BMI of less than 35. Encouraging results from mostly observational studies have sparked the interest in the surgical management of diabetes mellitus type 2.