We have reviewed thirty-three cases of accelerated hypertension associated with chronic total renal artery occlusion. During the process of progressive narrowing of the arterial lumen until complete occlusion, an exceptionally elevated blood pressure occurs when a critical reduction of renal blood flow is attained. Then the patient presents one or more of the following clinical manifestations: III-IV grade KWB retinal changes, hypertensive encephalopathy including convulsive attacks, stroke, heart failure, renal insufficiency. We have called this clinical event 'hypertensive vascular crisis'. Mostly in older patients an actual or anamnestic vascular crisis makes a diagnosis of chronic total renal artery occlusion highly probable.