Arterial hypertension represents a risk factor for cerebrovascular disease. It has been hypothesized that chronic hypertension may eventually result in small subcortical infarcts associated with some cognitive impairments. One hundred fourteen patients with primary systemic hypertension (PSH) and 114 matched subjects were selected. PSH patients were further divided in four groups depending upon the hypertension severity. In addition to the medical and laboratory exams, a neuropsychological evaluation was administered. The NEUROPSI neuropsychological test battery was used. An association between level of hypertension and cognitive impairment was observed. Most significant differences were observed in the following domains: Reading, executive functioning, constructional, and memory-recall. No differences were observed in orientation, memory-recognition, and language. Some neuropsychological functions appeared impaired even in the PSH group with the least risk factors. Cognitive evaluation may be important in cases of PSH not only to determine early subtle cognitive changes, but also for follow-up purposes, and to assess the efficacy of different therapeutic procedures.