The National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry captures information on interstage management of infants with hypoplastic left heart syndrome (HLHS). The purpose of this study was to identify interstage risk factors for increased resource use and adverse outcomes during bidirectional Glenn (BDG) hospitalization. All infants in the NPC-QIC registry (31 United States hospitals) undergoing BDG surgery were included (December 2009 to August 2010). Patient demographics, interstage variables, operative procedures, and complications were recorded. Days of hospitalization, ventilation, inotrope use, and complications were surrogates of resource use. Logistic regression analysis determined the associations between predictor variables and resource use. Of 162 infants, 105 (65 %) were males. At BDG, the median age was 155 days (range 78–128), mean weight-for-age z-score was −1.6 ± 1.1, mean length-for-age z-score was −1.5 ± 1.7, and mean preoperative oxygen saturation was 78 % ± 7 %. Caloric recommendations were met in 60 % of patients, and 85 % of patients participated in a home-surveillance program. Median days of intubation, inotrope use, and hospitalization were 1, 2, and 7, respectively. There were 4 post-BDG deaths and 55 complications. In multivariate analysis, lower weight-for-age z-score, female sex, and aortic atresia with mitral stenosis were associated with a higher risk of BDG complications. Meeting caloric recommendations before BDG was associated with fewer hospitalization days. Lower weight-for-age z-score was an independent and potentially modifiable risk factor for BDG complications. HLHS infants who met caloric recommendations before BDG had a lower duration of hospitalization at BDG. These data justify targeting nutrition in interstage strategies to improve outcomes and decrease costs for patients with HLHS.