A new Doppler time index of myocardial performance (Tei index) has been studied as a useful predictor of global cardiac function. It is defined as (a-b)/b, where a is the interval between end and onset of the mitral inflow, and b is the ejection time of left ventricular outflow. However, the Doppler time intervals are not measured on the same cardiac cycle. We compared the tissue Doppler imaging (TDI)-derived Tei index, which can be measured on the same cardiac cycle, with the conventional Tei index by pulsed wave Doppler method in healthy persons(n=36) and patients with diastolic dysfunction(n=39). At the septal and lateral mitral annulus from the apical 4-chamber view, time interval between end and onset of mitral annular velocities during diastole (a쨈) minus the duration of the systolic wave (b쨈) divided by b쨈, that is (a쨈-b쨈)/ b쨈, is defined as TDI-tei index. Results: TDI-Tei index and the Tei index were significantly higher in patients with diastolic dysfunction than healthy controls. The TDI-Tei index at the septal and lateral annulus correlated well with the Tei index (r= 0.6, r=0.57, respectively, p<0.001) and showed a good correlation with other echocardiographic parameters of diastolic function. In conclusion, we demonstrate that the TDI-Tei index correlates well with the conventional Tei index with the advantage of simultaneous recording of systolic and diastolic velocities and well differentiate between normal and diastolic dysfunction.