The use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with a range of renal effects, including interference with fluid and electrolyte homoeostasis. Common adverse effects are generally mild and transient; less common but more severe effects include reversible renal insufficiency, interstitial nephritis and papillary necrosis. Any of these effects can influence the clinical course of patients at risk because of illness, debility or age. Acute renal failure associated with NSAID use has been reported to account for up to 15.6% of cases of drug-induced renal failure. NSAID-induced haemodynamic renal failure is virtually always reversible with appropriate management; the relatively rare complications of interstitial nephritis and papillary necrosis are more often irreversible. NSAID-related impairment of kidney function is probably due in large part to inhibition of prostaglandin synthesis. Use of a prostaglandin E1 (PGE1) analogue has been suggested to prevent some of the adverse renal effects of NSAIDs in patients at high risk, an interesting possibility that deserves further evaluation.