Treatment results of 9,741 cases of gastric cancer treated at the Cancer Institute Hospital, Tokyo during the past 42 years were retrospectively analyzed. Resectability was 89.6% (94.1% for 1960–1988) and operative mortality was 1.9% (1.5% for 1960–1988). Five-year survival rate was 48.5% (54.9% for 1960–1988) for all cases, 68.8% (73.1% for 1960–1988) for patients with curative surgery, and 4.7% (4.9% for 1960–1988) for those with noncurative surgery. Curative rate was improved twofold among patients with curative gastrectomy. Postoperative adjuvant chemotherapy had a marginal benefit for stage II and III disease. Improvement could be attributed mainly to the relative in crease in early gastric cancer, and partly to the extended surgeries for stage III and IV cases, such as systemic lymphadenectomy and combined resection of involved adjacent organs. Multimodality therapy is expected to control the relapse of peritoneal dissemination (14.2%) and hematogenous metastasis (8.9%).