Seventy-two patients who underwent gastric banding for extreme obesity were followed for a mean of 30 (range 12-54) months. The mean weight loss after 1 year was 41 kg. About two-thirds of the patients had only minor complaints postoperatively, but the others had complications, some of which were serious. Two patients died. Complications related to the banding technique necessitated 33 reoperations in 22 patients. The most common cause of reoperation/complication was functional stenosis of the upper pouch outlet, but only 3 of 22 revisional operations were successful. Reduction in band tension resulted in fewer reoperations but also less weight loss. The incidence of complications and the poor outcome of revision indicate that gastric banding should still be regarded as an experimental operation. Peroperative measurement of all technical details and careful and frequent follow-up examination are necessary in the search for an optimal technical procedure, giving good weight loss with a minimum of complications.