Although transthoracic echocardiography (TTE) is the cornerstone of noninvasive cardiac imaging in the detection of cardiac source of emboli, transesophageal echocardiography (TEE) provides additional information for the identification of most causes. We report a case with a floating thrombus in the right coronary sinus of Valsalva, with complicated peripheral arterial embolism and renal infarct. Due to the high velocity of the blood flow, the formation of thrombus in the coronary sinus is extremely rare. This may, however, be a cause of embolism and a TEE examination should be included to detect potential cardiac source of embolism.