Abstract The literature relative to aneurysm of the renal artery has been reviewed. To date, the total number of aneurysms reported has reached 175. The fact that one-third of the cases have been reported within the past five years is undoubtedly the result of better diagnostic methods and the maintenance of a higher index of suspicion with respect to this lesion. The most reliable signs in the diagnosis of aneurysm of the renal artery include the presence of the calcific ring shadow on roentgenographic examination of the abdomen, and the presence of a vascular bruit, thrill or pulsating mass in the abdomen. The use of abdominal arteriography is invaluable in the diagnosis of this renal vascular lesion. The complications of renal artery aneurysm include renal damage, cardiovascular abnormalities and rupture of the lesion, which was fatal in twenty of the twenty-four cases in which this complication occurred. Hypertension, which was noted in forty-one cases, was relieved in many of these by nephrectomy. Other cardiovascular abnormalities noted in the presence of arteriovenous aneurysms were similarly relieved. Once aneurysm of the renal artery is diagnosed, surgical intervention offers the only hope of cure. While death was noted eventually in almost all the untreated cases, only 14 per cent of the operated cases terminated fatally, with most of the deaths being due to hemorrhage. Only 4.5 per cent of the patients undergoing nephrectomy died, and operation was life saving in many instances. None died after aneurysmectomy. Aneurysm of the renal artery is therefore an important lesion, and should always be considered in cases of unexplained hypertension or hematuria. It is hoped that this review will stimulate further interest in this renal vascular lesion so that more cases might be diagnosed which otherwise would be overlooked.