The results for the first 101 consecutive patients who had selective vagotomy and a drainage procedure performed for duodenal ulceration between 1967 and 1971 are presented. Seventy-four patients were followed up for five to nine years, 13 patients were lost to follow-up for part of the five-year period, and 14 patients died during follow-up. Six patients developed recurrent ulcers. Five of these recurrent ulcers were observed in patients in whom the vagotomy was not tested for completeness during the operation; this represents a recurrence rate of 10%. One patient, in whom testing was used at operation, developed a recurrent ulcer; this represents a recurrence rate of 2%. There was a statistically significant difference in the rate of recurrence between the group tested during operation and that not tested.