The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) is a Federation composed of national associations of bariatric surgeons and Integrated Health professionals. Currently, there are 72 official member societies of IFSO. IFSO is a scientific organization that brings together surgeons and integrated health professionals, such as nurse, practitioners, dieticians, nutritionists, psychologists, internists and anesthesiologists, involved in the treatment of morbidly obese patients. One of IFSO’s main goals is to support its members in aspects directly related to their profession. One of IFSO’s main activities is the organization of the yearly World Congress, which provides a forum to exchange knowledge on surgical treatment of severely obese patients, to present new techniques, research and concepts, and to meet the experts in the field. IFSO has also produced a number of guidelines, such as “Selection criteria for patients”, “Minimal requirements for bariatric surgeons”, and statements on morbid obesity and its treatment and is committed to the creation of a system for accreditation of individual surgeons and bariatric centers around the globe. The main goal of IFSO is the optimisation of the treatment of severely obese patients.