We report a case of non-Hodgkin's lymphoma (NHL) presenting with acute renal failure. A-56-year-old male was admitted to our hospital on October, 1997 with fever and renal dysfunction. Physical examination showed no abnormality except for hepatomegaly . Body surface lymphadenopathy was not observed. Computed tomography (CT) of the abdomen showed markedly enlarged kidneys bilaterally and a mass of soft tissue density, which was considered as a swelling lymph node, around the aortic artery. The renal biopsy revealed parenchymal involvement of the NHL cells without normal tubulo-interstitial structure, but the glomeruli were almost intact . Our case rapidly fell into oliguria and acute renal failure, hence needed hemodialysis . After chemotherapy was performed, his renal function gradually improved and the kidney became smaller on subsequent CT. Unfortunately, the patient happened to suffer from methicillin-resistant staphylococcus aureus (MRSA) infection in a neutropenic state and died. Necropsy revealed recovery of the renal interstitium without residual NHL cells . Renal lymphoma without any other organ or nodal involvement is a rare type of NHL, which considered primary renal lymphoma (PRL). However, we believe this case to have been a result of lymphomatous infiltration of the kidneys in disseminated lymphoma .