Jejuno-ileal bypass has been widely used for the surgical treatment of morbid obesity since 1954, but from 1978 onwards the operation has met with increasing disfavor, especially in the USA as a result of its unacceptably high complication rate. From 1982 onwards, 235 morbidly obese patients had a side-to-side jejuno-ileal bypass in our Department. Our data concerning weight loss and the overall incidence of complications show that jejuno-ileal bypass can still play a role in the surgical treatment of morbid obesity.