SummaryTen reports arc reviewed, presenting a total of 2 1 cases of acutc renal failure, ascribed to sulphinpyrazone therapy, usually early after myocardial infarction. A minority of these patients had a sulphinpyrazone induced allergic acute interstitial nephritis. Although acute uric acid precipitation may play a pathogenetic role, the arguments in favour of this mechanism are not convincing. It is suggested that in some cases an inhibition of vasodilatory renal hormones (prostaglandins and/or kallikrein kinins) could mediate renal functional im pairmcnt. Renal function should be closely monito red in patients taking this drug.