The patient with obstructive jaundice has an increased risk of developing renal failure. The commonest clinical situations in which this is seen is after surgical operation, as a result of percutaneous cholangiography or in association with severe ascending cholangitis. The risk of acute renal failure is decreased by ensuring adequate hydration and maintaining a high urine flow, if necessary using mannitol or some other osmotic diuretic. In patients undergoing percutaneous cholangiography, prophylactic antibiotics are probably indicated. Early surgery to control severe ascending cholangitis may be life saving and also prevent the development of renal failure.