Primary gastrointestinal lymphoma primarily confined to gastrointestinal tract is relatively rare disease accounting for approximately 1 4 percent of all gastrointestinal malignant dis- ease, and the concurrent malignant lymphoma of the stomach, duodenum and colon, especially cecum is very rare in reported cases. We had experienced a 43 years old man with malignant lymphoma of the stomach and duode- num and cecum, and he was treated by chemotherapy (MACOP B). So, we reported here with review of literatures. (Korean J Gastroenterol 1994; 26: 353 357)