Abstract Objective Pediatric patients who undergo repair of congenital heart diseases on cardiopulmonary bypass are at great risk of postoperative bleeding. The major causes of bleeding are thrombocytopenia, platelets dysfunction, hemodilution and increased fibrinolysis during cardiopulmonary bypass (CPB). Non-surgical postoperative bleeding occurs due to micro-vascular bleeding from pericardial and mediastinal tissues when blood comes in contact with non-endothelial surfaces of the Cardio-Pulmonary Bypass (CPB) machine, compounded by liberal use of heparin and a complex interaction of humoral and cellular pathways. Aim of the Work The aim of the study is to asses if there is potential benefit of intrapericardial topical application of tranexamic acid when it is combined with the intravenous administration in reduction of postoperative bleeding after pediatric cardiac surgery on cardiopulmonary bypass (CPB). Patients and Methods Type of the study: Interventional, randomized and double blinded clinical trial. Study Setting: The operating theaters of Ain Shams University Hospitals. Study period: Over one year (from March 2020 to March 2021). Standard management: Intravenous Tranexamic acid (TxA) injection. Results The estimated blood loss postoperatively in first 24 hrs. Were less in the combined group than the IV group. Requirements of blood transfusion also were statically significant in combined group than IV group from aspects of volume of PRBCs transfusion, Total number of patients exposed to transfusion and transfusion rate. There is no difference regarding ICU stay and need of surgical re exploration. Conclusion The combined use of low dose IV and topical intrapericardial tranexamic acid in children with congenital heart disease undergoing on pump cardiac surgery reduced the risk of post-operative bleeding and need for blood products transfusion when compared to the administration of IV tranexamic acid only suggesting a potential benefit of topical tranexamic acid in hemostasis.