Tetralogy of Fallot (TOF) remains the most common cause of congenital cyanotic heart disease occurring in approximately 2700 patient annually. It is considered the most common cardiac malformation responsible for cyanosis after 1st year of age. According to the importance of CHD specifically TOF, our study is aiming to compare between the diagnostic tools that were used commonly i.e. echocardiography and cardiac catheterization for their specificity, sensitivity and significant results.