The prognostic significance of aortic mobile debris detected by transesophageal echocardiography (TEE) in patients without history of embolism has not been established. A mobile aortic arch mass was found by TEE in a 59-year-old man with coronary artery disease, and with rheumatic mitral valve disease, and with no embolic symptoms. The patient was anticoagulated for 6 weeks and the mass was no longer seen on repeated TEE. He had no embolic symptoms during 9 months of follow-up. Different therapeutic approaches to mobile aortic debris are discussed and anticoagulant treatment of asymptomatic cases is advocated.