Background: Pulmonary regurgitation frequently occurs after surgical correction of Tetralogy of Fallot. To date, reliable quantification has not been possible, the current gold standard for measuring is cardiac MRI. For older patients with repaired TOF, pulmonary valve replacement may lead to improved right ventricular volumes and function. Objective assessment of RV function is therefore essential in the clinical follow-up of patients with repaired TOF. Measurement of myocardial velocities and myocardial performance (Tei) index by tissue Doppler imaging is a powerful tool for assessing the right ventricular and left ventricular systolic and diastolic function.Methods and results: 25 patients with repaired TOF were compared to 17 age and sex matched healthy controls, they underwent echocardiographic and CMR evaluation within 3 months of each others. The study demonstrated a statistically significant derangement of tissue Doppler and Cardiac MRI parameters with significant correlation between TDI and CMR parameters in detection of early myocardial dysfunction in asymptomatic repaired TOF patients. And that echocardiographic CW Doppler derived methods for quantification of PR (PR/diastole and diastole- PR) among different echo methods have the highest sensitivity, specificity and diagnostic accuracy in discriminating between hemodynamically significant and insignificant degrees of PR.Conclusion: CW Doppler is an accurate method for the noninvasive, volumetric quantification of pulmonary regurgitation after surgical correction of Tetralogy of Fallot. TDI PW velocities and Tei index are powerful tools in detection of early myocardial dysfunction in asymptomatic repaired TOF patients