A 10-day-old child with hypoplastic left heart syndrome (HLHS) underwent first-stage palliation for HLHS, Norwood procedure with a Sano modification, i.e., placement of a right ventricular to pulmonary artery (RV-PA) conduit. The patient developed progressively worsening systemic oxygen desaturation in the immediate postoperative period. Stenosis of the proximal RV-PA conduit was diagnosed by echocardiography. In the catheterization laboratory stent placement in the conduit was performed. This resulted in increased systemic oxygen saturation. The patient was eventually discharged from the hospital with adequate oxygen saturations.