Pediatric in-hospital cardiac arrest (IHCA) has been reported in 1-3% of pediatric intensive care unit (ICU) admissions and up to 6% of children admissions to the cardiac ICU. In the last 25 years, the survival to hospital discharge after pediatric IHCA has improved from 9% to 13.7% up to 35%. The improvement in outcomes was attributed in part to the application of ECMO as a rescue strategy when prolonged conventional CPR cannot restore spontaneous circulation. We report a case of a 4-month-old patient with a history of ventricular and septal defects, with left to right shunt and enlargement of left heart chambers that underwent surgery for the closure of the atrial and septal defects, and experienced complications that led to the use of ECMO in response to a prolonged cardiac arrest.