Patients with unexplained stroke or other embolic phenomena are often referred for echocardiography. The aortic arch is not usually visualized in detail during routine echocardiography; however, with the introduction of transesophageal echocardiography, this area may be seen with great resolution. We recently studied three patients who had embolic events, and transesophageal echocardiography showed a new and unexpected finding; large, protrusive plaques in the aortic arch and descending aorta, which have mobile projections that move freely with the blood flow. These lesions could be responsible for embolic syndromes, especially after catheter manipulation in the aorta.