Pure mitral stenosis (MS) affects left ventricular function as a result of myocardial and mechanical factors, we examined the left ventricular (LV) long axis function of the patient with pure mit`ral stenosis and normal global systolic function as assessed by ejection fraction (EF%).This study was designed to:- evaluate patients with MS by means of Tissue Doppler imaging (TDI) in patients with MS by assessing Myocardial Performance Index (MPI) and myocardial velocity during systole, early and late diastole. Also to evaluate whether LV dysfunction affects and correlates with pulmonary artery pressure (PAP).A total of 40 patients with estabilished diagnosis of MS (mean age: 43 ±10 years) and 40 healthy individuals (mean age: 29±7 years) were included in this study. Echocardiography equipped with TDI function was performed on each participant. The mitral valve area (MVA) and PAP were measured. Myocardial velocities were recorded at 4 different sites (septum, lateral, anterior and inferior) of the left ventricle by TDI. The positive systolic velocity when the mitral ring moved towards the cardiac apex and two negative diastolic velocities when the mitral annulus moved towards the base away from the apex were measured. TDI was used to evaluate iso-volumetric contraction time (IVC), iso-volumetric relaxation time (IRT) and ejection time (ET) at two different sites of the mitral annulus (lateral and septum). The MPI was calculated with the formula [(ICT+IRT) / (ET)], the mean MPI was found by dividing the sum of the MPI values into two. Patients with pure MS were compared with healthy participants, and the relationship of TDI variables with (MVA) and PAP were evaluated.The psitive systolic myocardial velocities of the left ventricle indicating LV systolic function were found to be significantly lower in patients with pure MS and MPI indicating LV systolic and diastolic function to be sugnificantly higher in patients with pure MS. A significant positive correlation could be established between MVA and systolic myocardial velocities (septum, lateral, inferior, anterior) (r=0.815, p=>0.01 ; r=0.821, p>0.01 ; r=0.815, p>0.01 ; r=0.676, p>0.01 ; respectively) whereas a significant negative correlation (r=-0.840, p>0.01) was established between MVA and MPI as well as between PAP and myocardial systolic velocities (septum, lateral, inferior, anterior) (r=0.754, p>0.01 ; r=-0.690, p>0.01 ; r=-0.742, p>0.01 ; r=-0.514. p>0.01 ; respectively) , PAP was also found to be singificantly positively correlate with MPI (r=0.855, p=0.01). This study shows that pure MS affects LV performance on long axis. The results indicate that the decrease in LV performance is caused by both functional and myocardial factors.