Background. There is growing recognition that postoperative pulmonary regurgitation may result in early or late progressive right heart failure. Method. A technique for fashioning an autologous monocusp pulmonary valve from the wall of the pulmonary artery was developed. The monocusp valve was fashioned from the anterior wall of the main pulmonary artery, and the remaining defect was filled with autologous pericardium. The procedure was performed in 8 dogs and 5 children. Results. Early follow-up and serial echocardiographic assessment in both dogs and children proved the functionality of this monocusp pulmonary valve. All valves were pliable and demonstrated mild to moderate pulmonary stenosis and insufficiency. Conclusions. Construction of the autologous monocusp pulmonary valve is a feasible technique, and the valve performs efficiently. The acute performance in the canine model was excellent, and preliminary midterm results in the clinical study are reasonable. It is logical to assume that the monocusp, being an integral part of the arterial wall, will retain its viability and share in the subsequent growth of the pulmonary artery. Should follow-up studies demonstrate its long-term competence, this autologous valve may provide a good solution for various forms of pulmonary regurgitation and be useful in pulmonary autograft replacement of the aortic valve.