Subjects with high normal blood pressure (BP) have a different progression rate to hypertension and a higher cardiovascular risk compared to individuals with normal BP. Microalbuminuria has been shown to be associated with an increased risk of cardiovascular morbidity and mortality in not only patients with diabetes or hypertension, but also the general population. Therefore, we assessed the incidence of microalbuminuria and cardiovascular risk factors as well as factors that influence microalbuminuria in two groups of prehypertension. We selected 2,678 prehypertensive subjects (1,689 men, 989 women), none of whom had a past history of diabetes or hypertension, from visitors to the health promotion center at Kangbuk Samsung Hospital between January and December 2005. Urine albumin excretion was measured by an immuno-radiometric assay in a morning urine sample. The incidence of microalbuminuria in the high normal BP group was higher than in normal BP group (4.9% vs. 2.8%, p=0.009). Subjects with high normal BP were older and had a higher incidence of males as well as the metabolic syndrome; higher waist circumference, body mass index, triglyceride, fasting blood glucose, uric acid and ferritin, and lower high density lipoprotein cholesterol were more common in the high normal BP group than in subjects with normal BP. Multiple logistic regression analysis showed that the high normal BP category had an independently significant association with microalbuminuria (table 1.)(Odds ratio=1.692, 95% CI; 1.097-2.611). Our findings suggest that more positive treatment strategies might be needed for individuals with high normal BP for the early prevention of cardiovascular disease.