A mesenteric diffuse large B-cell lymphoma which also involves the liver is very rare. We describe herein a mesenteric diffuse large B-cell lymphoma with hepatic involvement successfully treated by the combination of surgical resection and multiagent chemotherapy. A 77-year-old man was referred to our hospital because of a right lower abdominal tumor. Abdominal computed tomography showed a mass in the mesenterium at the ileocoecal region and multiple mass in the liver. Gallium scintigram showed focal hot uptake at the ileocoecal region and multiple areas of increased Gallium uptake in the liver. With the diagnosis of a mesenteric tumor with liver metastases, a laparotomy was performed. By an intraoperative pathological examination, non-Hodgkin's lymphoma was suggested. The mesenteric mass was completely resected, but additional operative procedures were not done to the liver. After the operation, the patient was determined to have Stage IVB diffuse large B-cell lymphoma, and chemotherapy based on the CHOP-like regimen was given. After the 8th course of such chemotherapy, he was confirmed to have achieved a complete remission by abdominal computed tomography and Gallium scintigram.The Stage IV mesenteric diffuse large B-cell lymphoma involving the liver seems to be an indication for combination therapy of surgical resection and multiagent chemotherapy.