Of the population of a small Tyrolean village, 185 (56%) of the 329 inhabitants over 40 years were investigated by means of Doppler and duplex sonography, electroencephalography (EEG), electrocardiography (ECG), and neurological examination. Four subjects (2%) previously had a transitory ischemic attack (TIA) or stroke in the carotid territory. Sonographically detectable abnormalities in one or more extracranial arteries were present in 42 (23%) persons. Of the 14 subjects with more than slight abnormalities in the common or internal carotid artery two were symptomatic. Two additional cases with TIA or stroke did not show relevant lesions on sonographic examination. The presence of narrowing in the extracranial artery was not related to risk factors (hypertension, smoking, obesity) or abnormalities on ECG and EEG. This study shows 1) that the clinical relevance of ultrasound screening of the carotid arteries in an average population is 15%; 2) that significantly more patients with TIAs or strokes are found in the group with more severe sonographic findings (p = 0.001) than in the group with normal ultrasound results.