We have compared hypertensive target organ damage with home blood pressure readings (HBPs) and with office blood pressure readings (OBPs) in 100 patients with mild to moderate essential hypertension. The correlation between blood pressure levels and hypertensive target organ damage in HBPs and OBPs were similar (r = .42, p less than 0.001 for systolic HBPs; r = .33, p less than 0.001 for diastolic HBPs; r = .42, p less than 0.001 for systolic OBPs; r = .34, p less than 0.001 for diastolic OBPs). In most instances, HBPs were lower than corresponding OBPs. Among individual patients whose OBPs were identical, HBPs in some instances differed strikingly. Optic fundi abnormalities were significantly more severe in patients whose systolic HBPs were 150 mmHg or greater, than in those whose systolic HBPs were less than 150 mmHg (p less than 0.05). Hypertensive complications did not differ among office hypertensive patients who were normotensive or borderline hypertensive at home, from the differences of OBPs. We concluded that overall hypertensive complications were equally related to HBPs and OBPs, but patients with discrepancies between HBPs and OBPs had fewer hypertensive complications. Thus, both OBPs and HBPs should be considered in deciding therapy.