The risk factors for superior vena cava (SVC) obstruction after pediatric orthotopic heart transplantation (OHT) have not been identified. This study tested the hypothesis that pretransplant superior cavopulmonary anastomosis (CPA) predisposes patients to SVC obstruction. A retrospective review of the Pediatric Cardiac Care Consortium registry from 1982 through 2007 was performed. Previous CPA, other cardiac surgeries, gender, age at transplantation, and weight at transplantation were assessed for the risk of developing SVC obstruction. Death, subsequent OHT, or reoperation involving the SVC were treated as competing risks. Of the 894 pediatric OHT patients identified, 3.1% (n = 28) developed SVC obstruction during median follow-up of 1.0 year (range: 0 to 19.5 years). Among patients who developed SVC obstruction, 32% (n = 9) had pretransplant CPA. SVC surgery before OHT was associated with posttransplant development of SVC obstruction (p <0.001) after adjustment for gender, age, and weight at OHT and year of OHT. Patients with previous CPA had increased risk for SVC obstruction compared with patients with no history of previous cardiac surgery (hazard ratio 10.6, 95% confidence interval: 3.5 to 31.7) and to patients with history of non-CPA cardiac surgery (hazard ratio 4.7, 95% confidence interval: 1.8 to 12.5). In conclusion, previous CPA is a significant risk factor for the development of post-heart transplant SVC obstruction.