Background: Modified Blalock-Taussig Shunt is the most commonly used palliative shunt procedure in congenital heart disorders and is associated with significant morbidity and mortality. Aim: to improve the outcome following this surgical intervention. Subjects and Methods: Data about all children undergoing Modified Blalock-Taussig Shunt in Suez Canal University Hospitals and Cairo University Specialized Children Hospital in the time interval between March 2014 and February 2015 has been collected in three phases; pre-intra-and post-operatively then analyzed statistically. Results: Mortality in our study was 50%. The main risk factors for mortality in our study were weight urgency pre-operative prostene infusion cardiopulmonary bypass graft size and wound infection. Regarding shunt occlusion weight shunt size and intra-operative administration of protamine were statistically significant risk factors. Conclusion: Mortality rates decreased significantly with increasing weight. Cardiopulmonary Bypass graft size and wound infection were noted to be definite risk factors for mortality. Regarding acute shunt occlusion risk factors of statistical importance were weight intra-operative protamine and graft size.