Ten adult white patients (21-75 years old; six women, four men) presented with large cell lymphoma of the liver. Each complained of abdominal pain and/or an abdominal mass, and five had B-symptomatology of weight loss, fever (one patient), and night sweats (three patients). At laparotomy (eight patients) or by computerized tomography, liver-spleen scan and lymphangiogram (two patients with percutaneous liver biopsy only), the liver was the sole site of involvement, although subsequent staging procedures revealed bone marrow involvement in three patients. Initial biopsy interpretation was incorrect in four cases which were diagnosed as poorly differentiated carcinoma. Although uncommon, the differential diagnosis of primary liver lymphoma should be entertained when patients present with solitary (three cases) or multiple (six cases) liver defects, particularly when alpha-fetoprotein and carcinoembryonic antigen levels are normal. One patient had diffuse hepatomegaly. Treatment included biopsy (eight patients) or resection (two patients) followed by combination chemotherapy. All patients are alive from 0 to over 10 years (mean, 2.4; median, 1.8 years): six in complete remission, two with less than 6-months follow-up, and two with recurrent lymphoma. Examination of this group of patients along with 19 cases identified in the literature suggests that this is a more treatable disease than primary liver carcinoma.