Three hundred and seventy-four cases of early gastric cancer in which invasion was limited to within the submucosa have been resected in our hospital during the past 15 years. The incidence of early gastric cancer was 31% among the total of 1,214 cases of gastric cancer operated on. There were 37 cases with multiple lesions and 5 cases with insufficient data. In this series, clinical investigations were performed in 332 cases excluding the above 42 cases.