Tests made of the sensory-perceptual, cognitive, and psychomotor abilities of untreated young patients with essential hypertension have revealed a pattern suggesting a slight functional impairment of the central nervous system. Reduced performance was most marked for those tasks requiring speed arid psychomotor coordination, particularly when the behaviors observed were self-initiated. Lowered scores were more evident among female hypertensives; no differences in performance by race were noted. The deficits measured by these sensitive tests do not appear to be great enough to intrude on everyday activity nor to impair work ability. Changes that may result from blood-pressure-lowering therapies will require further study. (Hypertension 4: 355–360, 1982)