Eight patients were operated upon for morbid obesity using strict criteria for operation. The average age was 35 years and average Broca's index 1.76. One patient underwent the Scott operation and seven the Buchwald-Varco procedure. There were neither postoperative deaths nor wound or bowel complications. The weight loss was 9.6% at the end of the 3rd postoperative week, and 24.6% at the end of the 4th postoperative month. Glycaemia and lipidaemia showed an important decrease upto the 3rd week postoperatively after which period this decrease became less marked. Electrolytes did not show any variation. Hepatic function tests indicated a slight increase at the 3rd postoperative week but normal levels at the later control. The frequency of diarrhoea varied between 8 and 10 liquid stools daily in the immediate postoperative period and 2-6 at the 4th month, without any pharmacological control. However, small intestinal shunts seem to create some favourable metabolic changes. Patient selection is important to the outcome of the operation. Long-term follow-up is mandatory since patients may develop medical complications.