Background: Risk assessment in heart transplantation is critical for candidate selection, but current models inadequately assess individual risk of postoperative mortality. We sought to identify risk factors and develop a scoring system to predict mortality after heart transplantation in children. Methods: The records of patients undergoing heart transplantation at our institution from 2010 through 2016 were reviewed. Clinical characteristics were recorded and compared between survivors and nonsurvivors. We used Cox proportional hazard modeling of factors associated with postoperative mortality to develop a risk factor score. Results: There were 74 patients who underwent heart transplantation at a mean age of 8.8 ± 6.6 years. Congenital heart disease was the most common indication, comprising 48.6% of the cohort. Overall mortality was 18.9%, with 10 of 14 dying within 30 days of the operation or during the initial postoperative admission (early mortality). Preoperative factors associated with overall mortality were single-ventricle congenital heart disease (hazard ratio [HR], 3.2; p = 0.042), biventricular assist device (HR, 4.8; p = 0.043), history of four or more sternotomies (HR, 3.9; p = 0.023), panel reactive antibody exceeding 10% (HR, 4.4; p = 0.013), any previous operation at another institution (HR, 3.2; p = 0.038), and pulmonary vein disease (HR, 4.7; p = 0.045). Each risk factor was assigned a point value, based on similar magnitude of the HRs. A score of 4 or higher predicted mortality with 57% sensitivity and 90% specificity. Conclusions: In this single-center pediatric cohort, postheart transplantation mortality could be predicted using patient-specific risk factors. The cumulative effect of these risk factors predicted mortality with high specificity.