Clinicopathological review was made of 18 cases of malignant lymphoma of the stomach who were admitted to the hospital from April 1972 to December 1987. During the same period, a total of 1192 cases of malignant tumors of the stomach were surgically treated, accordingly, malignant lymphoma cases amounted to 1.5% of the total. The patients with the averaged age of 59.7 years included males and females at the same ratio. Preoperative diagnosis with assurance is so difficult that only 38.9% of the cases could be successfully diagnosed as gastric malignant lymphoma. Macroscopically, broken or surface type was more frequently observed, while histologically, all cases belonged to diffuse lymphoma, the large cell type being most frequently occurred. Prognosis of cases with stage I and n(-) is relatively favorable, however, a possible development of lymphonodus metastasis in high rate is recorded even in sm cases that might demand more aggressive operation and/or chemotherapy.