Gastric surgery as a definitive method of treatment for simple peptic ulcer has been practised on an increasing scale over the last 50 or 60 years. Despite operation complete relief may not result and the patient may present at widely varying periods afterwards with new or recurrent symptoms. Increasing age brings an increased risk of gastric cancer but the onset of this occasional sequel may be obscured by symptoms which may have followed more immediately after operation. The purpose of this paper is to describe our experiences in the radiological diagnosis of gastric cancer in 13 patients who had already had gastric surgery for simple peptic ulceration, eight having had a gastroenterostomy and five a partial gastrectomy.Records of individual cases of gastric cancer following gastroenterostomy appear in the literature from the mid 1920s onwards. Beatson gastric or duodenal ulcer. Eleven cases of gastric cancer were encountered among the patients previously operated on for duodenal ulcer, an average of 15 years after the gastroenterostomy. There were six cases of gastric cancer among those operated upon for gastric ulcer but five of the gastric ulcer cases were operated upon within two years of gastroenterostomy so it may be that the original diagnosis of simplicity was incorrect. Freedman and Berne (1954) record a collected series of 55 patients with gastric carcinoma of the gastroduodenal stoma and added a further three of their own. In their series 24 primary operations were for duodenal ulcer and 14 were for gastric ulcer, the reason being unknown in the remainder. The average interval between gastroenterostomy and the recognition of gastric cancer in their series was 17 years and in their personal cases the interval was from 26 to 40 years. Helsingen and Hillestad (1956) were able to obtain information about 229 patients who had had a partial gastrectomy for simple peptic ulcer from 10 to 35 years before: 11 cases of cancer of the gastric stump occurred at an interval of 20 years and 10 of these followed resection for gastric ulcer and only one for duodenal ulcer. They comment that the observed rate of carcinoma in gastric ulcer patients is about three times the expected rate and that in duodenal ulcer patients it is approximately the normal rate. De Jode (1961) reported 19 cases of gastric cancer following gastric operations, 12 following gastroenterostomy and seven partial gastrectomy in the 10 years 1949-58 at The London Hospital. Nine of his 12 gastroenterostomies were for duodenal ulcer and so were four of the seven partial gastrectomies; the remaining operations were for gastric ulcer. The interval between operation and gastric cancer was from 18 to 37 years in cases of gastroenterostomy and from two to 36 years after partial gastrectomy. In two cases occurring less than five years following the latter operation one patient had originally a duodenal ulcer and the other a gastric ulcer but in both the carcinoma was at the cardia and remote from the orig-117