In Japan, R2-gastric resection which consists of gastrectomy, omentectomy and complete removal of Group 1 and 2 regional lymph nodes has been generally accepted as the procedure of choice in the treatment of early gastric cancer during the past 20 years. As a result, surgical treatment for early gastric cancer patients has achieved a very good survival rate, 97.7% and 96.2% 5 and 10 years, respectively, after surgery. To determine a new rationale for surgical treatment for early gastric cancer, the relationship between various prognostic factors and postoperative prognosis in 1,200 patients with early gastric cancer was studied. The survival rate for patients with a single focus of cancer in the stomach was significantly higher than that for patients with multiple foci. The incidence of recurrence was very low (2.8%) as a whole and most recurrence was found in patients who have had invasion into the submucosa with regional lymph node metastasis. The characteristic mode of recurrence was hematogenous metastasis to the liver and lung. The majority of causes of death were non-malignant disease and multiple primary malignant neoplasms. As to the survival rate in relation to the extent of lymph node dissection, no significant difference in survival rate was observed among the three procedures R0-, R1- and R2-resection in single cancer regardless of cancer invasion through the gastric wall. The survival rate for intramucosal carcinoma without lymph node metastases and with Group 1 lymph node metastases in both single and multiple cancer was 100%. In addition, 125 patients with intramucosal polypoid cancer (types I and IIa according to the macroscopic classification of early gastric cancer) showed no lymph node metastasis and had 100% survival. Therefore, from the present study a new rationale for surgical treatment for early gastric cancer is recommended as follows: 1) In general, R1-resection is indicated for intramucosal carcinoma and R2-resection for submucosal carcinoma. 2) Local resection of the tumor or R0-resection with preservation of the regional lymph nodes is thought to be sufficient for an intramucosal polypoid carcinoma less than 2.0 cm in diameter.