The objective of this study was to determine if maintenance of systolic blood pressure (BP) within a high range or low range among treated hypertensive patients increases the risk of memory decline. Biennial neuropsychological evaluations were performed on 158 hypertensive subjects. Decline/year was measured on the Cued Selective Reminding test (total free recall and delayed recall) in three systolic BP groups (low-i.e., mean systolic BP during the follow-up period < 135 mm Hg; intermediate-i.e., 135 mm Hg < or = mean systolic BP < or = 150 mm Hg; high-i.e., mean systolic BP > 150 mm Hg). In total free recall, the three systolic BP groups had significantly different declines per year (P = .02), with patients in the high subgroup showing the greatest decline. In delayed recall, the three systolic BP groups also showed significantly different declines per year (P = .04), with patients in the low subgroup having the greatest decline. Chronically elevated systolic BP > 150 mm Hg is associated with accelerated memory decline compared to older treated hypertensive patients with systolic BP in an intermediate range. Chronically maintained systolic BP within a low normal range < 135 mm Hg in older treated hypertensive subjects may be associated with accelerated memory decline, specifically in a test of delayed memory recall, compared to patients with systolic BP in an intermediate range. Optimal regulation of systolic BP may be a potential modifiable risk factor to prevent or minimize memory loss in older hypertensive patients.