Background and Objectives : The Tei index is reported to be an indicator of global ventricular function. However, the diagnostic value of this index for the regional dysfunction is unknown. We aimed to investigate whether this index can be applied to the assessment of regional left ventricular (LV) dysfunction. Materials and Methods : Fifteen patients (mean 65 짹 9 years, 5 females) with a evidence of myocardial infarction by echocardiography were enrolled in this study. LV was classified into infarcted and non-infarcted wall based on wall motion analysis: akinesis or severe hypokinesis as infarcted and mild hypokinetic or normal wall motion as non-infracted wall. The Tei index, defined as the sum of isovolumetric contraction time (IVCT) and isovolumetric relaxation time (IVRT) divided by ejection time (ET), was measured in basal segment of each infarcted and contralateral non-infarcted wall using a tissue Doppler imaging of apical 2 and 4 chamber views. In addition, we measured the peak systolic velocity in each wall. Results : Among these patients, thirteen patients underwent coronary angiography, those findings were compatible with echocardiographic wall motion abnormalities. The mean left ventricular ejection fraction of all patients was 37 짹 9%. The Tei index of infracted segment was significantly higher than that of non-infarcted segment (0.82 짹 0.22 versus 0.65 짹 0.18, p=0.023). ET, IVCT, IVRT, and peak systolic velocity in the infracted and non-infarcted wall were 257 짹 43 versus 264 짹 46, p=0.361, 96 짹 27 versus 79 짹 32, p=0.023, and 124 짹 52 versus 106 짹 52, p=0.178, and 4.7 짹 1.4 versus 5.9 짹 1.4, p=0.029, respectively. A significant correlation was present between the peak systolic velocity and the Tei index of each infarcted and non-infarcted wall (r=0.52, p=0.04 and r=0.55, p=0.03, respectively). Conclusion : The Tei index which has been known as a indicator of overall cardiac dysfuction was also valuable index for the LV regional dysfunction.