<p>Interstage mortality remains high after introduction of right ventricle (RV) to pulmonary artery conduits to stage I palliation for hypoplastic left heart syndrome (HLHS). Prior studies have not shown long-term survival benefit with conduits, likely due to multiple factors including regurgitation contributing to decreased RV function. Valved conduits (VC) were introduced to address these limitations. The study aimed to assess differences in RV size and function using echocardiography during the interstage period between patients undergoing stage I palliation with VC versus non-valved conduits (NVC). We hypothesized patients with VC would have smaller increases in RV size and improved function. Twenty-five neonates with HLHS who underwent Stage I palliation with VC were compared to 25 neonates with NVC from 2013 to 2022. Primary outcomes were RV end-diastolic area (EDA) and function measured by fractional area change and global longitudinal strain. There was no difference in EDA increase one month post-operatively between groups, but the VC group had a smaller increase in EDA pre-stage II compared to the NVC group (3.23 v 4.38 cm², <i>p</i> = 0.01). Function was not significantly different pre-stage II: GLS in VC -16.0% v NVC − 18.7% (<i>p</i> = 0.39) and FAC in VC 41% v NVC 38% (<i>p</i> = 0.26). There was no difference in interstage cardiac events or mortality between VC and NVC groups. Patients with VC at Stage I palliation had smaller interstage increases in ventricular size compared to NVC, but no differences in functional parameters or outcomes. Larger, longitudinal studies are needed to further examine the hemodynamic benefits of VC in the interstage period and beyond.</p>