Objective: To determine the change in neurocognitive test performance in children with primary hypertension after initiation of antihypertensive therapy. Study design: Subjects with hypertension and normotensive control subjects had neurocognitive testing at baseline and again after 1 year, during which time the subjects with hypertension received antihypertensive therapy. Subjects completed tests of general intelligence, attention, memory, executive function, and processing speed, and parents completed rating scales of executive function. Results: Fifty-five subjects with hypertension and 66 normotensive control subjects underwent both baseline and 1-year assessments. Overall, the blood pressure (BP) of subjects with hypertension improved (24-hour systolic BP load: mean baseline vs 1 year, 58% vs 38%, P <.001). Primary multivariable analyses showed that the hypertension group improved in scores of subtests of the Rey Auditory Verbal Learning Test, Grooved Pegboard, and Delis-Kaplan Executive Function System Tower Test (P <.05). However, the control group also improved in the same measures with similar effects sizes. Secondary analyses by effectiveness of antihypertensive therapy showed that subjects with persistent ambulatory hypertension at 1 year (n = 17) did not improve in subtests of Rey Auditory Verbal Learning Test and had limited improvement in Grooved Pegboard. Conclusions: Overall, children with hypertension did not improve in neurocognitive test performance after 1 year of antihypertensive therapy, beyond that also seen in normotensive controls, suggesting improvements with age or practice effects because of repeated neurocognitive testing. However, the degree to which antihypertensive therapy improves BP may affect its impact upon neurocognitive function.