One hundred and eighty-seven men, aged twenty to eighty years with an average of forty-eight years, underwent surgery for perforated duodenal ulcer. Seventeen received an immediate definitive procedure; none died. Nine (5 per cent) of the remaining 170 who had omentopexy died one to fifteen days postoperatively. They were older and waited longer. One hundred and twenty-one patients (76 per cent) were adequately followed. Thirty-nine (32 per cent) had "acute" perforation and eighty-two had "chronic" perforation. Twenty-four (30 per cent) of the latter underwent definitive operation within three months without mortality. Overall, 25 per cent of the ninety-nine patients followed after omentopexy required reoperation within twelve months. However, only three (8 per cent) of the thirty-nine with "acute" perforation required operation as compared with twenty-one (37 per cent) of the fifty-eight with "chronic" perforation. The main reason for early operation in the "chronic" group was obstruction; 21 per cent failed to empty their stomach immediately or soon after omentopexy and half as many either had pain or bled severely within twelve months and also required reoperation. The "acute" and "chronic" groups continued to differ in their need for further operation. Overall, 57 per cent of the ninety-seven patients required a definitive operation one to twenty-four years later. However, only ten of the thirty-nine patients (26 per cent) in the "acute" group required definitive operation as compared with forty-five of the fifty-eight patients (77 per cent) in the "chronic" group. Outlet obstruction of the stomach was the main indication for definitive surgery in twenty-six of the fifty-five (47 per cent) reoperations. This high incidence of gastric obstruction after omentopexy was not peculiar to our institution since, over the past six years, eighteen patients having omentopexy elsewhere had to be operated on for this complication. We recommend that patients with "chronic" perforation should not undergo omentopexy but rather immediate vagotomy and a drainage procedure.