In an attempt to reduce mortality in gastric stump carcinoma a defined cohort of operated peptic ulcer patients was followed up with an endoscopic screening programme. From 1930 and through 1960, 1575 patients were operated on for peptic ulcer disease at the Dept. of Surgery in Lund, Sweden. Of 838 still alive in January 1973, 682 were selected for geographical reasons and were offered endoscopic screening with biopsy at regular intervals. Three hundred and fifty-four patients came to the first examination. The follow-up programme was individualized thereafter with screening at 1- to 3-year intervals, depending on endoscopic and histologic findings. The remaining patients have, since then, constituted a control group, followed up only through death certificates and the Swedish Cancer Registry. By December 1989, 202 patients in the screening group had died and 320 in the control group. During the 17 years of follow-up 12 patients in the screening group died of gastric cancer, compared with 14 in the control group, even though 17 cases of early gastric cancer were diagnosed and operated on in the first group, compared with only 2 in the latter. We conclude that regular endoscopic screening does not reduce gastric cancer mortality and can thus not be recommended in asymptomatic patients previously subjected to partial gastric resection due to peptic ulcer disease.