adequate flows and decompress the heart. Literature examining use of extracorporeal membrane oxygenation (ECMO) in this population consists of a single case series reporting no survivors. We report our experience providing ECMO in children with RCM or HCM at a large pediatric quaternary cardiac center. Between 2012 and 2022, five patients (four RCM, one HCM) were supported with seven ECMO runs. All patients were cannulated to ECMO with ongoing cardiopulmonary resuscitation. Four patients survived decannulation from ECMO (median support time 209 hr, interquartile range [IQR]: 48–265), of which three (60%) survived to hospital discharge after transitioning to a ventricular assist device (VAD) and undergoing orthotopic heart transplant (OHT). Two remain alive at long-term follow-up with normal or mildly impaired functional status. These findings suggest that while RCM and HCM have traditionally been considered contraindications to ECMO due to adverse outcomes, this population may be succe