Background: The aim of this study was to investigate aortic atheromas in stroke subgroups. Methods: Two hundred consecutive subjects had acute ischemic stroke confirmed by diffusion-weighted imaging (DWI) (195 cases) or computerized tomography (5 cases). Multidetector computed tomographic angiography (MDCTA) (16- or 64-slice) was used to detect atherosclerotic plaques in vessels. Patient data and diagnostic test results were recorded. Stroke subgroups (TOAST classification) were compared with respect to plaque features in the ascending aorta or aortic arch such as presence of at least I plaque, larger than 1 mm thick, multiple plaques, and plaque morphology (calcific, soft, mixed and ulcerated). Results: Of the patients, 20.3% were in the large-artery atherosclerosis (LAA), 29.4% had small artery occlusion (SAO), 23.8% had cardioembolism (CE), 6.6% had more than one potential cause found (MPC) and 19.8% had cryptogenic stroke (CS). Overall, 49.7% of patients had at least I plaque (any size) in the ascending aorta or aortic arch. The corresponding rates for subgroups were as follows: LAA 80%, SAO 50%, CE 44.7%, MPC 61.5% and CS 20.5% (p < 0.001). Subgroups also differed significantly with respect to presence of multiple plaques and plaques > 1 mm thick. Of all plaques 93% were mixed type, of which 19% were ulcerated. Conclusions: Almost half of the stroke cases had atheroma in ascending aorta or aortic arch and most them had a soft component. Subgroups LAA, SAO, and MPC had higher aortic atheroma density compared to CE and CS. (C) 2009 Elsevier B.V. All rights reserved.