A series of 19 neonates with persistent ductus arteriosus associated with right heart pathology such as pulmonary or tricuspid atresia (13 cases), left heart and aortic arch pathology (3 cases) and simple transposition of the great arteries (3 cases) is presented. The efficacity of an infusion of prostaglandins (PG E1, 0,05 /kg/min) in improving the clinical condition of the patients before surgery was confirmed. A rapid improvement in the blood gases (02 saturation) was obtained in right heart pathology. In children with the second group, the efficacity of PG depended mainly on the clinical state and degree of peripheral hypoperfusion before therapy. For this reason, the infusion should be instituted as soon as possible, even before confirmation of the diagnosis. PG were used in a newborn with simple transposition of the great arteries in association with balloon septostomy in order to obtain an earlier result with the latter procedure. The incidence of side effects was higher in this than in other reported series. The protocol of infusion and its surveillance are discussed. Prolonged infusion of PG is not advised as it was probably responsible for oedematous infiltration of the vessel wall in one child.