Histopathologic changes in the regenerative epithelia of 549 foci of gastric ulcer were studied. About 70 per cent of the regenerative epithelia revealed intestinal metaplasia of the so-called complete or incomplete type. Parietal cells and chief cells were occasionally observed in the regenerative epithelia of ulcers located in fundic gland areas or at fundopyloric gland borders. It is possible that the regenerative epithelium frequently reverts to intestinal epithelium during the regenerative process, later redifferentiating into normal gastric mucosa or remaining as intestinal metaplasia and that, thus, only a few foci of intestinal metaplasia are precancerous lesions.