Primary malignant lymphoma of the liver is extremely rare, and its preoperative or even premortem diagnosis is still difficult. The authors herein report a case of primary malignant lymphoma of the liver in a 51-year-old Japanese man. The findings at angiography were non-specific, but a hypoechoic mass with a halo was demonstrated by ultrasound sonography, which revealed rapid progression. The tumor volume doubling time was 9.6 days. An extended right hepatic lobectomy with lymph nodes dissection was done on the basis of a preoperative diagnosis of hepatocellular carcinoma, while the diagnosis based on immunohistological studies was T cell malignant lymphoma of the liver. After the adjuvant chemotherapy, the patient continues to be free of disease for three years and nine months. We herein describe the optimum methodology for making a preoperative diagnosis of primary malignant lymphoma of the liver. We also consider that a curative hepatic resection with adjuvant chemotherapy for primary malignant lymphoma of the liver is an adequate treatment for this disease.