Catheter-based interventional palliation of infants with hypoplastic left heart syndrome (HLHS) has been successfully used to stabilize infants awaiting orthotopic heart transplantation. The three critical palliative requirements for HLHS are ductal patentcy, left heart decompression, and the regulation of pulmonary flow. We reviewed our experience in 40 infants with ductal stenting, and 17 of these 40 infants underwent placement of internal pulmonary artery bands. The infants ranged in age from 2 days to 7 months and from 2.1 to 6.6 kg in weight. There was one procedure-related death after balloon septostomy. The duration of palliation was from 3 days to 1 year. Late survival was 75% with long-term palliation or transplantation. Experience and anatomy of the RV outflow tract/ductus arteriosus was related to technical complications. Infants with mesoversion (12%) were more likely to have procedural and late complications (65%). Internal pulmonary artery bands provide predictable and effective protection of the distal pulmonary artery bed. Pulmonary artery reconstruction was not required, and there were no late pulmonary artery stenoses. We conclude that interventional catheter-based palliation of HLHS has been proven in principle, and further gains in experience and technology will likely make this desirable in the majority of infants with hypoplastic left heart syndrome.