Objective: The extraluminal technique of pulmonary artery banding can be difficult to perform precisely in conjunction with cardiopulmonary bypass and is associated with a significant risk of band-related complications. We analyzed our results with an intraluminal technique of pulmonary artery banding in patients who required cardiopulmonary bypass for the performance of associated cardiac repairs. Methods: The medical records of 18 neonates and infants who underwent intraluminal pulmonary artery banding were retrospectively reviewed. A circular patch with a 3.0-mm, 3.6-mm, or 4.0-mm diameter fenestration was sutured to the inner circumference of the main pulmonary artery. Preoperative, intraoperative, and postoperative variables were reviewed to assess the efficacy and safety of the intraluminal technique. Results: Intraluminal pulmonary artery banding produced a consistent and significant reduction in the systolic pulmonary artery pressure (64.00 ± 12.24 to 16.53 ± 6.33 mm Hg, P <. 001), the systolic pulmonary artery pressure/systolic systemic pressure ratio (0.91 ± 0.10 to 0.19 ± 0.07, P <. 001), and the pulmonary flow/systemic flow ratio (4.32 ± 3.04 to 0.91 ± 0.49, P =. 015). There were no band-related anatomic complications. Two patients did require percutaneous dilation of the intraluminal pulmonary artery band before debanding to palliate systemic arterial desaturation. Conclusions: Intraluminal pulmonary artery banding is an effective palliative procedure that can be used in patients who require cardiopulmonary bypass for the performance of cardiac repairs in addition to placement of the pulmonary artery band.