Abstract-In people aged Ͼ80 years, the so-called very elderly, there is uncertainty about the relation between hypertension and cardiovascular morbidity. The aims of this study were to investigate whether hypertension in people aged Ͼ80 years is associated with target-organ damage, over and above the effects of age, and to determine whether ambulatory blood pressure monitoring (ABPM) could improve on conventional blood pressure monitoring (CBPM) in predicting target-organ damage. Investigations included echocardiographic measurement of left ventricular mass index (LVMI), brain magnetic resonance imaging assessment of periventricular hyperintensity (PVH), urinary albumin-creatinine ratio (ACR), aortic pulse wave velocity (PWV), and 24-hour ABPM. Forty-three subjects, at a mean age 84.3 years, were studied, 22 normotensive (NT) and 21 hypertensive (HT). CBP was 184/89 and 145/76 mm Hg in the HT and NT groups, respectively. In men, LVMI was significantly greater in HT subjects, 157Ϯ37 vs 123Ϯ15 g/m 2 in NT subjects (PϽ0.05). In women, LVMI was similar in both groups. Urinary ACR was greater in HT than in NT subjects (log ACR, 1.21Ϯ0.50 vs 0.95Ϯ0.23; PϽ0.05). Cerebral PVH grade was higher in the HT subjects (2.6Ϯ0.8 vs 2.2Ϯ0.9), although this difference was not significant. Aortic PWV did not differ between the 2 groups. ABPM was positively associated with urinary ACR and cerebral PVH, independent of its correlation with CBPM. In advanced old age, HT is associated with evidence of target-organ damage. ABPM can improve on CBPM in predicting very elderly subjects with HT target-organ damage.