Objective: Left ventricular ejection fraction (EF) and left ventricular (LV) end-systolic diameter measurements are the most widely accepted and utilized methods to demonstrate LV dysfunction in patients with mitral regurgitation (MR). However, these parameters still have many drawbacks in predicting early LV dysfunction. This study investigates the clinical usefulness of tissue Doppler echocardiography technique in detecting early disturbance of myocardial contractility in asymptomatic patients with chronic, severe MR and normal LV ejection fraction values. Methods and Results: Regional systolic peak velocities of mitral annular motion during the ejection phase of systole ( SW2) were obtained at the mitral annuli of the ventricular septal, lateral, anteroseptal, posterior, anterior and inferior wall sites in the long axis in 31 asymptomatic patients with severe MR ( with a regurgitant volume of more than 50 ml) and with EFs more than 60%. The patients were grouped according to their dP/dt values ( more or less than 1300 mmHg/s) estimated non-invasively by using continuous Doppler wave of MR SW2 measurements of Group I were higher than Group II in all of the analyzed segments. The difference was statistically significant for all of the segments. SW2 values of the whole study group was moderately correlated with dP/dt measurements in all of the analyzed segments other than the interventricular septum. Conclusion: SW2 measurements in the long axis, which are considered to be relatively independent from afterload conditions may be helpful in early detection ( while EF is still in normal range) of LV systolic dysfunction during the follow-up of patients with chronic MR.