Objective: Since there is a difficulty in the assesment of right ventricular systolic function by 2D echocardiogrphy, a noninvasive, practical and, cost effective method is desirable. Tisse Doppler technique enables to visualize systolic and diastolic velocities of the tissue through sample volume replacement. In this study, we aimed to evaluate the relationship between tricuspid annular tissue Doppler velocities and right ventricular systolic functional. Materials and Methods: For this purpose, tricuspid annular systolic (S), early diastolic (E) and, late diastolic (A) velocities were obtained from 38 patients (23 with dilated cardiomyopathy, 15 with mitral stenosis, all of them in sinus rhythm) and 15 healthy control subjects by placing the pulsed wave sample volume at the junction of right ventricular free wall and tricuspid annulus. The time velocity integral (TVI) of S, peak velocity of S and isovolumic contraction time (IVCT) were compared with right peak velocity of tricuspid regurgitation and dP/dt calculated from the spectral tracce of this regurgitation. Results: A significant correlation was determined between RVEF and peak S velocity, S TVI and IVCT (r: 0.76, p<0.001, r: 0.82, p<0.0001 and r: -0.85, p<0.0001 respectively). The peak S velocity <12 cm/sec, S TVI < 2 cm and IVCT>75 msec yielded 76%, 84%, 92% sensitivity and 84%, 84%, 80% specificity for predicting the patients with right ventricular ejection fraction <40%, respectively. A significant and powerful correlation was determined between the peak S velocities and dP/dt in 19 patients whose tricuspid regurgitation could be clearly recorded (r: 0.88, p<0.0001). Conclusions: The analysis of tricuspid annular velocities obbtained by tissue Doppler technique is a practical method of the assessment of right ventricular systolic functions.