One hundred sixty-six patients with documented recurrent or marginal ulcers following previous ulcer operation were seen at Duke Medical Center and the Durham VA Hospital from 1950 through 1980. Patients with the diagnosis of gastrinoma were excluded from the series. Evaluation of initial operation for recurrent ulcer showed that the highest recurrence rate occurred following non-acid-reducing operations. Analysis of the symptom-free interval following initial ulcer operation showed a significantly longer interval prior to recurrent ulcer development following gastroenterostomy than other procedures, while resection and Billroth I reanastomosis showed a significantly shorter symptom-free interval than did other procedures. Endoscopy proved 85% sensitive in making the diagnosis of marginal ulcer, while upper GI series was 71% sensitive. Surgical treatment of 132 patients resulted in a 20.4% recurrence rate of second marginal ulcer, with a 2.3% mortality rate and a 10.6% morbidity rate. Second operation for recurrent ulcer in 24 patients yielded no deaths, a 12.5% morbidity rate, and a 29.2% recurrence rate. Average follow-up for the series was 12.3 years, and ultimate outcome of treatment showed, of patients not lost to follow-up, a 58.2% satisfactory to excellent rating, while 42.8% of patients had an unsatisfactory result of treatment.