Transcranial Doppler ultrasound (TCD) and computed tomography angiography (CTA) of 10 patients with middle cerebral artery territory stroke were studied. To obtain data from patients with presumed in situ middle cerebral artery (MCA) stenosis, the study excluded patients with a known source of cardiac emboli, significant carotid stenosis and classical lacunar syndrome. As the gold standard for this study, CTA demonstrated MCA stenosis in all patients (100%), while abnormal TCDs suggesting MCA stenoses were found in only six patients (60%). The stenotic sites differed among patients with normal and abnormal TCDs. Patients with false negative TCDs were found to have more distal lesions (distal M1 or M2 segment) whereas patients with TCD abnormalities tend to have more proximal lesions as demonstrated by CTA. It is concluded that an abnormal TCD is highly suggestive of stenosis of MCA. A normal TCD, however, does not exclude such a lesion, especially in patients with distal M1 or M2 stenoses. Therefore, TCD may not be the best screening test for intracranial vascular stenotic lesion in MCA territory stroke.