Background Extracorporeal membrane oxygenation (ECMO) support is often required in the management of perioperative congenital heart surgery (CHS) patients. However, 24-hour in-hospital congenital cardiac surgical coverage (24-CCSC) is not available at all institutions. The purpose of this study is to evaluate the effect of 24-CCSC on perioperative ECMO outcomes in CHS patients. Methods An institutional review board approved, retrospective review of 128 perioperative CHS ECMO patients at a single, quaternary care children's hospital between January 2003 and December 2012 was performed. Primary endpoints evaluated were mortality in children supported with ECMO after undergoing cardiac surgery and ECMO-related morbidity after initiation of 24-CCSC with advanced congenital cardiac surgical fellows. Patients were divided into 2 groups based on whether 24-CCSC was absent (cohort 1: January 2003 to July 2007) or present (cohort 2: August 2007 to December 2012) at the time of ECMO management. Results The surgical procedures performed were similar in both cohorts based on STAT Mortality Categories (5 Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories). The overall mortality rate in children supported with ECMO after undergoing cardiac surgery was 53%. This mortality was significantly reduced from 68% to 43% (p = 0.007) with 24-CCSC. Multivariate logistic regression analysis revealed that 24-CCSC (p = 0.009) and lower STAT Mortality Category (p = 0.042) were independent predictors of operative survival. Cardiac arrhythmias (36% to 16%; p = 0.012) and pulmonary complications (32% to 8%; p <0.001) were significantly reduced with 24-CCSC. Conclusions The presence of 24-CCSC significantly decreased the rate of mortality in children supported with ECMO after undergoing cardiac surgery, as well as cardiac arrhythmias and pulmonary complications for perioperative CHS patients receiving ECMO support. This study demonstrates that CHS programs would benefit from 24-CCSC in the care of this critically ill patient population.