To evaluate changes in frequency of orthostatic blood pressure (BP) reduction (orthostatic hypotension; OH) in elderly hypertensive patients (HT) before and after treatment for hypertension, we measured BP after supine for 10 min and standing position for 2 min, before and after treatment for 2 years by five kinds of antihypertensive drugs in 50 elderly normotensive subjects (NT) and each of 50 HT in double-blind study. Orthostatic hypotension was defined as 10% or more decline of supine mean BP, and the frequency of OH was in 27% of HT following BP reduction by any kinds of antihypertensive drugs. In conclusion, the reducing or normalized BP by treatment for hypertension in elderly HT decreases the prevalence of orthostatic hypotension.