Cerebrovascular events have high mortality and morbidity, especially in the elderly. Ischemia is the main cause and 30% of the ischemic events are embolic and of cardiac origin. The clinical picture is not always typical of the type of stroke, but diagnosis of the mechanism of the event determines treatment. Transesophageal echocardiography (TEE) is a sensitive procedure more appropriate for diagnosing emboli of cardiac origin than transthoracic echocardiography (TTE). We therefore compared TEE and TTE in the determination of the source of emboli in 65 patients with ischemic stroke but without significant atherosclerotic changes in their carotid arteries, and compared these findings with those in 50 patients without stroke. 68% of the patients had potential sources of emboli according to TEE, compared to only 15% according to TTE. In the control group only 24% had potential sources of emboli by TEE. The findings were: clots in the left atrium, severe aortic atheroma, patent foramen ovale with paradoxical shunt, spontaneous echocardiography contrast, vegetations and mitral valve prolapse. The study showed that TEE is better than TTE in detecting the etiology of embolic stroke in those with normal carotid arteries, thus determining appropriate management.