The authors report the case of a neonate with transposition of the great arteries (TGA) with pulmonary stenosis (PS) and intact Interventricular septum. The child was born at full term without a prenatal diagnosis with cyanosis developing at the 12th hour. After emergency atrioseptostomy, detransposition was performed on the 6th day. Commissurotomy and shaving of the much thickened bicuspid pulmonary valve was also performed. The postoperative course was complicated by a non-compliant left ventricle. After two months, myocardial ischaemia and persistent obstruction of the outflow tract led to severe cardiac failure and the death of the child. TGA with PS and intact interventricular septum is a very rare cardiac malformation. The prognosis is closely related to the anatomy of the pulmonary valve and the impact on the left ventricle. The therapeutic options are complex and are discussed in relation to this case.