['Multiple brain infarcts are often seen on diffusion-weighted images in cardioembolic stroke patients. Recently, mobile aortic plaques (MAPs) have been proposed as embolic sources. However, the clinical characteristics of patients with MAPs are unclear.', 'We prospectively studied patients with acute ischemic stroke who underwent transesophageal echocardiography. The patients were classified into 3 groups based on transesophageal echocardiography findings: atheromatous aortic plaques <4 mm, atheromatous aortic plaques > or =4 mm without mobility, and MAPs. Based on their diffusion-weighted image findings, the patients were divided into 3 subgroups: (1) single lesion; (2) multiple lesions in a single vascular territory; and (3) multiple lesions in multiple vascular territories. We assessed the clinical characteristics and the diffusion-weighted image findings of stroke patients with MAPs.', 'One hundred sixty-seven patients (age, 70+/-12 years; 98 males) were enrolled; 128 (77%) had atheromatous aortic plaques <4 mm, 27 (16%) had atheromatous aortic plaques > or =4 mm, and 12 (7%) had MAPs. Older age, male gender, coronary artery disease, and cerebral arterial stenotic lesions were seen most frequently in patients with MAPs. On diffusion-weighted image findings, patients with MAPs were most frequent in the multiple lesions in multiple vascular territories group (P=0.001). On multiple logistic regression analysis, the National Institutes of Health Stroke Scale score (OR: 1.11; 95% CI: 1.01 to 1.22; P=0.039), arterial stenotic lesions (OR: 4.71; 95% CI: 1.35 to 16.41; P=0.015), and mobile aortic plaques (OR: 14.44; 95% CI: 2.87 to 72.66; P=0.001) were significantly associated with the multiple lesions in multiple vascular territories group.'] Are mobile aortic plaques a cause of multiple brain infarcts seen on diffusion-weighted imaging?