Background and Objectives: Spontaneous echocontrast (SEC) has been considered as a predisposition to thromboembolism and cerebrovascular accident, particularly in patients with mitral valve stenosis and chronic atrial fibrillation (AF). However, there have been no reports on the prevalence and role of SEC in dilated cardiomyopathy (DCMP). The aim of this study was to investigate the prognostic usefulness of SEC in predicting stroke in patients with DCMP. Subjects and Methods: Between October 2001 and June 2007, transthoracic echocardiography (TTE) with tissue harmonic imaging (THI) was performed in patients with DCMP. THI reduces near-field and side-lobe artifacts, so it is known to improve recognition of cardiac masses, including thrombi and SEC. DCMP was defined by ventricular dilation and contractile dysfunction (ejection fraction ��� 40%). We tried to find correlation of the echocardiographic findings such as SEC and other echocardiographic parameters with clinical outcomes of stroke or death in patients with DCMP. Results: This study included 202 consecutive patients (122 men and 80 women, average age 62.8 짹 15.4 years) with DCMP (mean ejection fraction 27.6 짹 7.7%). SEC in the left atrium (LA) or the left ventricle (LV) was observed in 16 patients (7.9%). There were no differences in LA dimension (46.1 짹 7.1 vs. 42.1 짹 8.4 mm) and LV end-diastolic dimension (59.2 짹 10.4 vs. 60.3 짹 7.9 mm) between patients with and without SEC. Stroke occurred in 4 (25.0%) of patients with SEC and in 9 (4.8%) of patients without SEC. Patients with SEC by THI on TTE had a significantly higher occurrence rate of stroke (odds ratio = 6.6, p = 0.012) than those without SEC. There was no difference in mortality rate between patients with and without SEC (6.3% vs. 6.5%). Conclusion: These results suggest that SEC by THI through TTE has a strong association with stroke in patients with DCMP. Therefore, this study may help in the risk stratification of cardiac embolism in patients with DCMP. And with this basis, we suggest a more aggressive anticoagulation treatment for these patients.