The gastric remnant can be regarded as a model to investigate the events of gastric carcinogenesis of intestinal type. Histologic changes precursor of the malignancy develop in higher incidence in the postoperative stomachs than in non-resected ones. 316 patients hemi-gastrectomized for peptic ulcer were assessed by an endoscopic-histologic study to provide further informations on the sequential chain of histologic lesions that precede the development of cancer. The anastomosis was by far the commonest diseased area at endoscopy, particularly in the patients with a Billroth II resection (p < 0.0004). The 10% of the 233 patients biopsied evidenced a normal gastric mucosa, in the others Superficial Gastritis 74%, Chronic Atrophic Gastritis 36%, Cystic Dilatation 52%, Foveolar Hyperplasia 29%, Intestinal Metaplasia 39%, moderate-severe Dysplasia 6% as single abnormality or variously associated were observed. The stoma was the most damaged area at histology. The occurrence of the DC, the FI and the IM at the anastomotic site was significative (p values between 0.02 and 0.001). The earliest postoperative histologic lesion was the CAG, evidenced, in mean 13 years after operation, the latest the DC observed in mean 18 years after surgery (p < 0.004). The IM, the IF, the CD, and the dysplasia in association with the CAG were observed at postoperative intervals shorter when non-associated with CAG (respective p value: NS, < 0.03, < 0.0002, NS). The probability of transition from an histologic lesions to a more advanced one in our patients was similar to that of a non resected population at medium--high risk of gastric cancer.