PURPOSE: The aim of this study is to evaluate the clinical value of myocardial segmental thickness variability (STV) measured by echocardiography in distinguishing ischemic cardiomyopathy (ICM) from nonischemic dilated cardiomyopathy (NIDCM). METHODS: This study included 120 patients diagnosed with dilated cardiomyopathy, divided into ICM (n = 43) and NIDCM (n = 77) groups based on coronary angiography. Traditional echocardiographic parameters, STV, and regional wall motion abnormalities (RWMA) were compared. The diagnostic value of STV was assessed using receiver operating characteristic (ROC) curve analysis. RESULTS: There were no significant differences in traditional echocardiographic parameters between the groups. The NIDCM group had a significantly higher mean STV compared to the ICM group. An STV threshold of 0.768 provided a sensitivity of 86.0% and a specificity of 94.8% for distinguishing ICM from NIDCM. Combining STV with RWMA improved diagnostic accuracy. CONCLUSION: STV measured by echocardiography is a valuable, noninvasive tool for differentiating between ICM and NIDCM, offering high sensitivity and specificity. This approach enhances diagnostic precision, supporting its use in clinical practice to guide appropriate treatment strategies.