<p>Extracorporeal membrane oxygenation (ECMO) is an infrequently utilized, resource intensive life-sustaining therapy used in critically ill children, and frequently those with congenital heart disease. However, reports on the use of ECMO pre-cardiac-surgical intervention as a bridge to an operation are limited. This study evaluated contemporary outcomes in patients supported with ECMO prior to an index cardiac surgical intervention. This is a single center retrospective cohort study from a pediatric quaternary care hospital evaluating demographic and clinical characteristics associated with mortality in a cohort of patients requiring ECMO support as a bridge to an index cardiac surgical intervention. The primary outcome was survival to hospital discharge. Over the 13-year study period there were 37 ECMO runs prior to an index cardiothoracic surgical procedure, representing 6.6% (37/547) of ECMO runs and 0.3% (37/12440) cardiac-surgical admissions in pediatric patients. No clinical covariates were statistically associated with the need for ECMO post a surgical intervention. However, the need for post-operative ECMO was associated with 2.5 times greater risk of mortality with multivariable logistic regression showing the need for post-operative ECMO to be an independent predictor of mortality. Diagnostic category was also important with specific cardiac diagnoses associated with improved survival. The need for ECMO to rescue a clinical decompensation prior to an index cardiac surgical interventions is a rare scenario with diagnosis-specific considerations, the potential for surgical correction of the underlying pathophysiology, and successful immediate post-operative decannulation being key determinants of survival in this population.</p>