Thirty-three patients with primary gastric lymphoma over a period of 32 years were studied. Endoscopic findings indicated that there were many cases of multiple lymphoma in the stomach, or with extensive tumor-infiltration, and that it was necessary to carefully inspect the entire stomach to determine the scope of resection and improve diagnostic accuracy. It is also particularly important not to damage the tissue during biopsy and to take deep large specimens from the ulcer margin, surrounding wall, and area of erosion. As compared clinicopathologically with gastric carcinoma, primary gastric lymphoma is found more frequently in younger females, with invasion of the entire stomach and extensive lymph node infiltration. By performing adequate resection of lymph nodes, as is done for gastric carcinoma, and administering appropriate combination chemotherapy, postoperative longterm results were similar to, or better than, those obtained with gastric carcinoma.