In the two-year period, 1955 and 1956, 104 selected hypertensive patients were subjected to aortography. Of these, 30 were found to have unilateral or bilateral obstructive lesions of the renal artery. Most of these lesions were considered to be the primary cause of the hypertensive disease but some aggravated an existing essential hypertension. Most of the obstructive lesions were arteriosclerotic plaques. There were six instances of poststenotic aneurysmal dilatation. Currently the most important means of recognizing renal artery disease is renal angiography accomplished by means of translumbar aortography. Of the 30 patients, 19 had either nephrectomy or corrective renal artery surgery, which usually resulted in remission of the hypertensive vascular disease.