Consensus has not been achieved regarding the impact of multiple cerebral infarcts on neurobehavioral status. To evaluate cognitive function in patients with multiple cerebral infarcts, we administered a comprehensive neuropsychological test battery to 23 consecutive male patients with clinical and brain computed tomographic findings consistent with at least two separate areas of cerebral infarction. Based on brain computed tomographic findings, patients were classified as having either mixed (#i = 12) or lacunar (n = ll) infarcts. Results of these two groups were compared with those of 11 age-, sex-, and education-matched controls with no clinical or brain computed tomographic evidence of cerebrovascular disease. The mixed group had significantly lower mean scores than the controls for every cognitive domain tested. The lacune group showed cognitive impairment on most neuropsychological measures but did not differ from the controls in the attention domain. Although some degree of cognitive impairment was detected by the neuropsychological test battery in virtually every patient, only seven of 23 (30%) had Mini-Mental State Examination scores indicating dementia (< 24). We conclude that virtually every patient with multiple cerebral infarcts has some degree of cognitive impairment but that only a minority can be classified as demented if the Mini-Mental State Examination is used as the primary defining examination.