During the past 7 years, 170 morbidly obese patients have been subjected to a biliopancreatic diversion. Mean weight loss achieved over 2 years was greater than 70% of excess weight and was maintained. Early complications were rare. The most common side-effects are discussed. The re-operation rate because of these side-effects was 7%. Eating normal meals, together with a stable weight loss, has provided these patients with a better quality of life.