The Nature, pathophysiology and clinical significance of periventricular white-matter lucencies revealed by computed tomography and magnetic resonans scans called "leuko-araiosis" are not well understood. We studied 57 patients with leukoaraiosis detected by computed tomography scans and 45 of them had cerebrovascular disease. There were 47 (82.5%) with hypertension and 31 (54.4%) patients with hyperlipidemia. We found decline in cognitive func- tin in 25 paients using the mental status test of Kokmen et al. Ten of them were severely demented. We suggested that control of vascular risk factors is important for controlling leukoaraiosis that may lead to intellectual impairment.