We histologically examined 17 lesions from minute gastric cancer (less than 5 mm in diameter). Flat or IIb type was frequently seen in minute cancer (47%); the depressed type was predominant in ordinary early gastric cancer (72%). Differentiated adenocarcinoma was noted more often in minute cancer (88%) than in ordinary early gastric cancer (61%) or advanced cancer (45%). Differentiated type minute cancer was frequently associated with severe atrophic gastritis (93%) and intestinal metaplasia (73%). There was no evidence for the preexistence of chronic peptic ulcer, because no fibrosis was present in the gastric wall beneath the minute cancerous lesions.