To clarify the relationship between large-vessel disease and asymptomatic cerebral infarction (ACI), we evaluated atherosclerotic changes in intracranial and extracranial arteries in adults with and without ACI. Subjects were 142 apparently healthy persons with ACI on magnetic resonance imaging (MRI) (ACI group) and 605 age matched persons without cerebral infarction on MRI. The 605 age-matched persons were divided into 380 persons with cerebrovascular risk factors (RF group) and 225 persons without cerebrovascular risk factors (NC group). Intracranial arteries (internal carotid artery, main trunks of the middle cerebral artery, and basilar artery) were examined by magnetic resonance angiography (MRA), and extracranial carotid arteries were investigated using B-mode ultrasonography. Stenosis of 25% to 49% in intracranial arteries detected on MRA was significantly more frequent in the ACI group (16%) than in the RF group (8%) or NC group (4%) (P < .05 and P < .001, respectively). On B mode ultrasonography, the prevalences of <25% stenosis (29%) and 25% to 49% stenosis (7%) in extracranial carotid arteries in the ACI group were significantly greater than those in the NC group (16% and 2% respectively, P < .05), whereas >/=50% stenosis was significantly more frequent in the ACI group (6%) than in the RF group (2%; P < .05). There was no statistically significant difference in prevalence of stenosis in intracranial and extracranial large arteries between persons with ipsilateral stenosis and infarction and persons with contralateral stenosis and infarction. We conclude that potential major cerebral vessel disease frequently coexists in persons with asymptomatic lacunar infarction.