During the period 1979-80, 20 patients with morbid obesity underwent a gastric bypass procedure in our department. The selected patients were under 50 years old and were overweight by 45 kg or more. Previously, all the patients had unsuccessfully followed prolonged dietary regimes, some had tried dental splinting, and one had undergone three unsuccessful jejunoileal bypasses. The surgical technique used in two cases was transection of the stomach and gastrojejunostomy. In 18 cases, a gastric stapling procedure was performed. the upper gastric pouch was restricted to 5% of the entire stomach, and the gastrojejunostomy was limited to a 12-mm diameter. In the case with the failed jejunoileal bypass, dismantling of the intestinal bypass, reanastomosis, and a gastric bypass were performed in one stage. Weight loss averaged 8 kg/month for three months after the intervention, and then decreased to 2 to 4 kg/month. Laboratory studies after 6 and 12 months showed no deviation from normal. The use of the gastric bypass procedure, which does not involve metabolic complications or serious side effects, in refractory obesity results in a satisfactory long-term weight reduction, and an improvement in the quality of life.