Objective:  The aim of the study was to compare diagnostic accuracy of tissue Doppler imaging (TDI) and conventional Doppler echocardiography in diagnosis of left ventricular diastolic dysfunction in patients with cardiac syndrome X. Methods:  Our study was designed as cross-sectional study. In our study, we compared 35 patients with cardiac syndrome X (19 female, mean age 47.2±7.3 years) with 33 healthy persons as control group (18 female, mean age 49.5±7.1 years) with no coronary artery disease and having no ischemic complaints or findings at exercise test. Left ventricular systolic function was found by considering mean values of modified Simpson method for left ventricular ejection fraction and TDI assessment of systolic wave peak velocity. The diastolic function of left ventricle was assessed with conventional echocardiography and TDI. Unpaired t test for independent samples or Mann-Whitney U test were used for comparison of continuous variables, Chi square test - for comparison of categorical variables. To define the capability of predicting diastolic dysfunction for conventional Doppler echocardiography and tissue Doppler imaging ROC curve analysis was applied.   Results:  Left ventricular ejection fraction and systolic wave peak velocity were similar for both groups. Conventional Doppler echocardiographic measurements for left ventricular diastolic functions delineated the more frequent presence of diastolic dysfunction in cardiac syndrome X group As compared with controls (48% vs 18%; p<0.01). When both methods used for assessing diastolic dysfunction, it was found more apparent (66% vs 24%; p<0.01). When ROC curve was drawn for conventional Doppler echocardiography the AUC was0.623, the sensitivity and the specificity were  49% and 76%,  respectively. When the same was done for TDI the values were AUC=0.669, the sensitivity - 66% and the specificity - 68%. Conclusion:  Our study revealed the deterioration of left ventricular diastolic function in patients with cardiac syndrome X. We found TDI echocardiography was more sensitive to delineate left ventricular diastolic dysfunction in this category of patients when compared with conventional Doppler echocardiography.