An assessment of outcome has been made after highly selective vagotomy performed by two surgeons on 174 patients. The median time to followup was 36 months (range 3-94). The group comprised 74% males and 26% females (median age 45 years, range 19-75). Assessment was by review of medical history, endoscopy (irrespective of presence or absence of symptoms) and questionnaire. Symptomatic ulcer recurrence had already been diagnosed in 16 patients (9%). There were 2 unassociated deaths and 14 patients remained untraced. The remaining 142 patients were assessed by questionnaire and asked to undergo an endoscopy. One hundred and nineteen agreed to endoscopy and ulcers were found in 11 patients (9%). Five were sited in the duodenum and 6 in the stomach. Duodenitis was found in 30% of patients. Patients with ulcers in the pyloric region were at significantly greater risk than the general group for developing a recurrence. Patients who agreed to endoscopy (119) underwent Visick grading prior to endoscopy. A poor correlation was found between ulcer recurrence and Visick score. The "asymptomatic" recurrence rate of 9% following highly selective vagotomy should be considered when assessing the outcome of the surgery.