A 46-year-old, previously fit man underwent standard primary chemotherapy and then further standard chemotherapy, followed by high-dose chemotherapy (without total body irradiation) and an autologous marrow transplant for relapsed non-Hodgkin's lymphoma. He also received antibiotics, antifungals and antivirals during this time. He developed episodic renal impairment with remissions, but his renal function never returned to baseline. Renal biopsy demonstrated the lesion to be due to thrombotic microangiopathy; he was treated by an angiotension II receptor antagonist, low-dose aspirin and warfarin. Seven years later the renal function remains mildly impaired but stable. This unusual iatrogenic nephropathy is discussed.