IntroductionPostoperative bleeding is a common complication in congenital heart surgery. We aimed to evaluate effects of topical and intravenous tranexamic acid (TXA) administration on postoperative hemoglobin and bleeding in children with acyanotic congenital heart disease (CHD). MethodsIn this randomized clinical trial, 50 acyanotic CHD children were allocated into two groups of topical (n = 25) and infusion (n = 25). Children in the infusion group were given intravenous TXA 50 mg/kg−1 after sternotomy. Children in topical group were given 50 mg/kg−1 TXA added to 20 mL of saline intrapericardially before sternal closure. Primary endpoint of study was comparison of postoperative hemoglobin and bleeding between topical and infusion groups. A linear mixed model (LMM) was used to estimate longitudinal changes in postoperative endpoints. ResultsWe did not observe significant differences in children's characteristics between two groups. Also, intraoperative and postoperative outcomes did not differ between two groups but children with intravenous TXA experienced significantly longer intubation time than topical children (P = 0.047). LMM analysis revealed that postoperative bleeding in topical group was lower compared to infusion group (P = 0.036). Also, age of children had a significant effect on mean changes of hemoglobin during postoperative care (β = −0.27, P = 0.030). No children died and none had serious postoperative complications such as seizures and reoperation. ConclusionsWe found that topical TXA is not superior to intravenous administration in management of blood loss. Also, no additional effect was found about topical TXA in further reducing transfusion rates and postoperative complications in acyanotic CHD children undergoing cardiac surgery.