The authors report the case of a young man operated for tetralogy of Fallot and in whom surgical treatment of severe stenosis of the origins of the right and left pulmonary arteries had failed. Correction of these stenoses was obtained by implanting percutaneously an endoprosthesis in the right pulmonary artery with a good result: control angiography showed that the stenosis had disappeared and an increase in the right pulmonary artery diameter from: 5 to 11 mm, and the left pulmonary artery diameter from 7 to 14 mm. Perfusion pulmonary scintigraphy showed equal flow in the two lungs.