A 43-year-old patient of occult adult T-cell lymphoma (ATL) presenting with systemic illness and progressive renal failure due to lymphomatous infiltration of kidneys is described. The striking feature observed was destructive infiltration of the kidneys, by malignant CD4 cells, virtually replacing the normal renal architecture. The diagnosis of lymphoma was made by renal biopsy. Clinical features typical of ATL were hypercalcemia, lytic bone lesions, and profound wasting and inanition. The patient died rapidly despite attempted therapy. The case illustrates the potential of ATL for direct renal parenchymal destruction.