The psychomotor performance of 25 elderly patients with mild to moderate hypertension (aged 62-78 years, SBP = 162-212 mmHg; DBP = 98-124 mmHg) was compared with 25 age-matched controls (SBP = 110-160 mmHg; DBP = 64-92 mmHg). The hypertensive subjects did not have evidence of target-organ damage and were on no antihypertensive treatment at the time of assessment. Performance on a range of tests: symbol/digit substitution test (SDST) (34.3 vs. 39.5, P < 0.01), continuous attention test (CAT) (33 vs. 36.2, P < 0.01), choice reaction time (CRT) (270 ms vs. 320 ms, P < 0.01), paired word association test (PWAT) (4.1 vs. 7.0, P < 0.001) and inspection time threshold (INSP) (158 ms vs. 52 ms, P < 0.001), showed significant impairment in the hypertensive group compared with controls. These differences did not correlate with the duration of hypertension or degree of BP elevation. The impairment in hypertensive subjects was stable over a four week period. These results suggest the occurrence of a functional and possibly reversible impairment of psychomotor performance in elderly hypertensive patients which may have implications for antihypertensive treatment.