The neuropsychological test performance of hypertensive and normotensive subjects was compared at three times of measurement over a 10-year period. The tests used were among those that are most sensitive to brain impairment in the Halstead-Reitan battery. In addition to individual test measures, a widely used clinical index of battery-wide performance--the Average Impairment Rating (AIR)--was used. Hypertensives exhibited lower mean levels of performance on the AIR at all times of measurement. However, the Blood Pressure Group x Time of Measurement interactions were not statistically significant, indicating that hypertensives and normotensives did not exhibit a differential rate of change (decline or improvement) over time. Hypertensives also performed more poorly for a measure of learning set formation (categories test) and two tests of memory for forms experienced by touch only (tactile perception memory and localization tests). However, Blood Pressure x Time of Measurement interactions were not observed for these measures.