A clinical, endoscopic and histological study was performed in 300 patients with chronic gastric erosions. The male-female ratio was 4:1. The antrum was the preferential site of erosions. Chronic erosions were classified into two categories: “active” (with a dark clot or whitish coat of fibrin) and “inactive” (covered by a normal pink mucosa). All the lesions showed foveolar hyperplasia, partial obliteration of the lamina propria by fibrous and smooth muscle bundles, a greatly thickened muscularis mucosae and an increased number of submucosal thick-walled vessels. In the “active” stage the central umbilicated area was covered by a collection of granulocytes, while in some of the “inactive” erosions the central depression showed the presence of a channel-like structure penetrating into the lamina propria. In two cases the lesion mimicked a gastric adenomyoma. Gastric acid secretion was significantly increased in the tested patients as compared with normal. The similarity of the histological findings with those in ischemic conditions of the gastro-intestinal tract suggests that both hypersecretion and localized ischemia may play a role in the pathogenesis of chronic erosions.