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.