Left heart obstructive lesions, in particular interrupted aortic arch or severe forms of coarctation with hypoplasia of the aortic arch, are the main cause of cardiac failure in the neonate and are often at the root of multiple organ failure which worsens the prognosis. Based on a retrospective study of 35 neonates admitted between July 1984 and June 1994, the authors attempted to identify the prognostic factors for admission to the intensive care unit and the optimal timing for operation of these patients. All neonates with a ductus-dependent aortic obstructive lesion and severe multiple (at least four) organ failure, were included in the study. There was a high mortality (54%) including firstly 7 patients who died in the three days following admission to the intensive care unit (20%); this was so-called "medical" mortality for which there was no identifiable poor prognostic factor. On the other hand, the surgical mortality (12 out of 28 cases, 43%) was significantly different in neonates operated before recovery from multiple organ failure (72%) and those operated after recovery from multiple organ failure (17%). Based on these results, the authors propose a therapeutic strategy based on prolonged preoperative intensive care until the initial multiple organ failure is reversed rather than early surgery.