BACKGROUND: The present study was aimed at defining the topological characteristics of the carotid intima-media thickness (IMT) in hypertensives, and to delineate whether the characteristics were different from those of non-hypertensive vascular risk factors. METHODS: B-mode carotid ultrasonography was performed in 33 participants who were devoid of stroke, ischemic heart disease, and carotid plaques. Longitudinal carotid images were obtained at 6 angular sites, 0 degree indexed adjacent to the external carotid artery (ECA) side from axial image crossing both internal carotid artery (ICA) and ECA, and then 45 degrees, 90 degrees, 180 degrees, 225 degrees, and 270 degrees. From the level of the flow divider, with an interval of 5 mm, up to 15 mm proximally, all the carotid IMT was measured. The IMT was then analyzed according to the levels and angles and compared according to either of hypertension or non-hypertension vascular risk factors. RESULTS: The carotid IMT showed asymmetric distributions in both the hypertension and non-hypertension risk groups. The IMT difference according to hypertension was observed better in the right carotid artery than the left. The right carotid IMT in the hypertension group showed significantly higher values at the most levels, and especially at 0 degree and 180 degrees of angular sites. CONCLUSIONS: It is important to understand the different topological characteristics of the carotid IMT according to the presence of hypertension, for a better reproducibility and predictability of the ultrasonic carotid IMT measurement.