The presence of intrapulmonary arborization abnormalities in patients with pulmonary atresia and ventricular septal defect remains a therapeutic challenge. The aim of this study was to assess the value of procedures of pulmonary unifocalization, i.e. pulmonary unification, remodelling of the central pulmonary arteries and creation of an unifocal pulmonary blood supply, thereby resulting in complete repair. From october 1989 to october 1995, 27 unifocalization procedures were performed in 19 patients. The number of pulmonary segments dependant on non-communicating systemico-pulmonary collaterals was 14.7 +/- 5.4 per patient. The number of non-communicating systemico-pulmonary collaterals was 3.4 +/- 1.2 per patient. The Nakata index was 71 +/- 83 mm2/mm2. There were 3 deaths after an unifocalization procedure (mortality rate 15.8%). In 12 patients (63.2% of cases) a pulmonary arterial tree compatible with a complete repair was obtained. Eight complete repairs, with no mortality, following one or several pulmonary unifocalization procedures with a right to left ventricular systolic pressure ratio of 0.61 +/- 0.12 (range 0.4 to 0.75). Pulmonary unifocalization increases the recruitment of pulmonary segments and thereby the possibilities of complete correction in forms of pulmonary atresia with ventricular septal defect and arborization abnormalities of the pulmonary arterial tree.