Background: In repair of tetralogy of Fallot (TOF), the use of monocusp to protect the right ventricle from volume overload is debatable. Aim of work: Evaluates early outcome of pericardial monocusp in pulmonary position in transannular patch repair (TAP). Patients and Methods: 60 patients underwent TOF repair with TAP from June 2016 to December 2018 in Al-Azhar University Hospital and National Heart Institute, group I thirty patients without pericardial monocusp and group II thirty patients received it in pulmonary position. Results: We had Thirty-four male patients representing (56.66%). The mean age of our patients was 14.983±6.533 months. The mean aortic cross clamp time was statistically shorter in group I (P<0.001) without statistical significance in the mean Cardiopulmonary bypass time. Intensive care units stay was significantly shorter in group II than group I. The mean hospital stay in group I was 10.862±2.248 days which was longer than group II. In post-operative echo, the mean grade of PR in group I was 3.409± 0.734 and in group II was 1.654±0.629 and the mean TR in group I was 1.955±0.785 and in group II was 1.346±0.485. In follow up echo, the mean grade of PR was 3.448±0.686 while in group II was 2.241±0.830 and the mean grade of TR in group I was 1.690±0.712 while in group II was 1.345±0.814. Conclusion: A pericardial monocusp in pulmonary position is safe, effective and helps to protect the right ventricle from early hemodynamic consequences when transannular patch repair of TOF is done.