In 3 years seventeen patients presented to one unit with renal failure associated with the use of non-steroidal anti-inflammatory drugs (NSAID). Seven patients presented with acute renal failure, in four due to acute tubular necrosis and in three to acute interstitial nephritis; all recovered when NSAID treatment was stopped. Four patients presented with symptomless renal impairment discovered during routine follow-up in a rheumatology clinic; again all improved on withdrawal of NSAID. The remaining six patients presented with chronic renal failure, a disorder not previously associated with NSAID treatment. The pattern of renal disease associated with NSAID may be more extensive than has previously been recognised. A history of NSAID use should be sought in all patients presenting with unexplained renal failure.