Results of auscultation of carotid arteries have been reviewed in 200 adults patients with 332 carotid angiograms. Cases with abnormal cardiac bruits of supraclavicular buits were excluded. There was no case with stenosis of the external artery or significant anemia. 2. The present series of patients comprises : 100 with internal carotid artery (ICA) stenosis, 50 with ICA occlusion and normal contralateral ICA, 50 with cerebral space-occupying lesions. 3. A bruit was present in 80/132 ICA stenosis (60 per cent), 60/84 ICA stenoses reducing the lumen by more than 75 per cent (71 per cent), 20/48 ICA stenoses reducing the lumen by less than 75 per cent (41 per cent). It appeared likely that the presence of an ICA stenosis plays a role in the presence of a contralateral bruit where a contralateral stenosis or occlusion are present. 4. An ipsilateral bruit was present in 50/50 ICA occlusions. A contralateral bruit was present in 7 patients the ICA angiogram being normal. A bruit was present on both sides in 4 patients and it may be that some patients are somewhat apt to have bruits. 5. There was no bruit in 49 patients with normal carotid angiograms and a cerebral space-occupying lesion. Data from the present series suggest that where both ICA's are normal auscultation is falsely positive in less than 10 per cent of patients.
