Objectives - The aim of this study was to assess the role of transesophageal echocardiography in detecting the source of cerebral embolism in ischemic stroke patients and to evaluate the difference in occurrence of heart abnormalities in anterior and posterior circulation infarcts. Material and Methods - The study group included 104 patients, 51 males and 53 females with ischemic stroke without significant atherosclerosis in the carotid arteries. Age of the patients ranged from 14 to 82 years (mean 55). The clinical picture of stroke suggested the embolic etiology, 34 of them had atrial fibrillation. Transthoracic and transesophageal echocardiography were performed in all patients. All patients were separated as anterior or posterior circulation infarcts. The control group consisted of 100 patients aged from 14 to 73 years (mean 53) without stroke history. Results - Transesophageal echocardiography (TEE) examination revealed left atrial thrombus in 12%, left atrial spontaneous contrast in 16%, interatrial communication in 31%, mitral valve prolapse in 20%, atrial septal aneurysm in 14%, ventricular thrombus in 6% and aortic atheromas of 5 mm or more in size in 7% of stroke patients. In the control group left atrial spontaneous contrast was found in 10%, interatrial communication in 17%, mitral valve prolapse in 4%, atrial septal aneurysm in 8%, neither atrial nor ventricular thrombi were found. At least one abnormal TEE finding was present in 70 (67%) of stroke patients. Abnormal TEE findings were more often seen in patients with anterior circulation infarct than in those with posterior circulation infarcts, although the difference was not statistically significant. Left atrial thrombus and mitral valve prolapse occurred statistically significantly more often in stroke patients than in the control group. Conclusions - Echocardiographic examination is often abnormal in patients with ischemic stroke. The study did not reveal the statistically significant difference in the prevalence of abnormal transesophageal echocardiography findings between patients with anterior and posterior circulation infarcts.