Pulmonary atresias with ventricular septal defect, a right ventricular infundibulum and pulmonary artery separated by an imperforated membrane and a complete pulmonary tree with two branches in continuity are called "favourable" forms of this malformation. The authors studied 29 neonates, less than 1 month old, in whom the malformation was both ductus- and prostaglandin-dependent, prostaglandin infusion being essential for pulmonary flow and impossible to stop because of the resulting severe hypoxia. The choice of treatment depended on the anatomical form defined by angiocardiography. In the 19 regular forms with regular pulmonary arteries with little hypoplasia, percutaneous perforation-dilatation was successful in 3 out of 5 attempts with one secondary death and 2 good results leading to complete repair; anastomosis was performed in 9 cases with 3 deaths, 1 partial result and 5 good results which were followed by complete repair in 3 cases; primary complete repair attempted in 7 cases led to 1 death and 6 successes completed in 3 cases by reoperation for left pulmonary artery stenosis. In the 10 less favourable anatomical forms with stenosis or severe hypoplasia or the pulmonary branches, only palliative procedures were proposed: 2 perforations-dilatations which only gave partial results, 7 anastomoses with 1 death and 4 partial results; and 1 ventriculo-pulmonary connection without closure of the ventricular septal defect (good result). In view of the good results obtained over the 6 years of the study, the authors advise primary complete correction for the anatomically favourable forms of the malformation when weaning from prostaglandin infusion is impossible.(ABSTRACT TRUNCATED AT 250 WORDS)