We administered palliative procedures for hypoplastic left heart syndrome in three cases. One case underwent Van Prragh's procedure and two cases were subjected to Jonas's modification of Norwood's procedure. One of the latter cases with AS and MS survived. The pulmonary blood flow of the survivor was secured through a hole of 3 mm in diameter made between the posterior wall of the newly constructed pulmonary-aortic common tract and the heterogeneous pericardial patch used to close the distal end of the transected main pulmonary artery. The pulmonary blood flow had been maintained adequately for 15 months after the operation but the flow was decreased thereafter. Consequently, a modified Blalock-Taussig shunt was added at the age of 21 months. The patient is now waiting for Fontan procedure in the near future. We used a heterogeneous pericardium to supplement an anastomosis connecting ascending aorta, aortic arch, and proximal descending aorta with transected proximal main pulmonary artery. This procedure also served to supplement the defect of the distal end of the transected main pulmonary artery. The sufficient removal of coarctation of aorta is very important. No aneurysmal change of this pericardium has been recognized. However there still remains a slight stenosis at the proximal anastomosis between the pulmonary artery and the newly constructed common tract. To avoid this stenosis, we recommend an anastomosis of the transected proximal main pulmonary artery to the ascending aorta and then to the proximal end of the heterogeneous pericardial tract.(ABSTRACT TRUNCATED AT 250 WORDS)