The aim of this study was to evaluate an extended protocol of the large vessels using high-frequency duplex ultrasound (DUS) for detection of vessel wall inflammation. Fifty-eight patients performed a DUS examination where arteritis could not be excluded. All DUS examinations were performed using ACUSON S2000 TM ultrasound system (Siemens Medical Solutions USA, Inc.). High-frequency linear transducers were used (18L6 MHz, 9L4MHz) or curve linear for the aortic arch (6C2MHz). Carotid, vertebral, central neck arteries (subclavian, axillary, innominate) arteries, aortic arch and femoral arteries were studied. Circumferential, homogenous wall thickening, with or without a hyperechogenic stripe lining the innermost layer, were regarded as typical signs of arteritis. Intima-media thickness (IMT) was measured in the patients and a normal control group. The latest clinical updated diagnosis was assessed at least 6months after DUS. The DUS findings showed normal vessels (n=14), arteritis and atherosclerosis (n=13), atherosclerosis (n=15) and arteritis (n=16). The latter group had a significant increased IMT in the common femoral artery and the common carotid artery (mean 1·0± SD 0·3mm versus 0·6±0·2mm in the normal group (n=37), P<0·00001, 1·2±0·5mm versus 0·8±0·2mm in the normal group (n=40), P<0·00001). In the groups with sonographic signs implying arteritis (n=29), 20 patients had a clinical diagnosis of arteritis, whereas eight patients had another main diagnosis such as malignancy/other inflammatory or infectious disease complicated by inflammation of the vessel wall. One patient had multiple diagnoses and was not possible to classify. An extended ultrasound protocol for central neck and leg arteries could be of value for diagnosis of arteritis. In case of atypical vessel wall inflammation, other main diagnoses should be considered.