Introduction: Duration of conventional cardiopulmonary resuscitation (CPR) prior to ECMO cannulation (ECPR) has been shown to be associated with worse survival outcomes, yet conflicting reports exist. Hypothesis: ECPR patients who receive guideline-compliant CPR will have improved survival to hospital discharge (SHD) compared to patients who do not receive guideline-compliant CPR, regardless of CPR duration. Methods: Prospective cohort from PediRES-Q sites of IHCA in children ≤ 18 yo requiring ECMO to achieve ROSC. We assessed compliance of 60-sec chest compression (CC) epochs via metric data (Zoll R-series, Chelmsford, MA) with 2015 AHA guideline targets. Guideline-compliant CPR was defined as an IHCA with >60% epochs meeting compliance criteria for metric data. Differences were assessed utilizing Wilcoxon rank-sum and Chi-square tests. Logistic regression assessed the association between compliance and SHD, adjusting for age, arterial line, and duration of CPR. Results: From 10/2015 to 3/2019, 62 index ECPR events (> 5 epochs) in 20 infants (<1 yo), 24 children (1-<8 yo), and 18 adolescents (8-≤18 yo) with CPR quality metric data were utilized from 15 sites. Median CPR duration 52 mins (IQR 45,70), median weight 11.6 kgs (IQR 6.8,29.8), and 38/62 patients (61%) had a cardiac diagnosis. Guideline compliance was not associated with SHD. Adjusting for age, presence of arterial line, and duration of CPR, guideline compliance was not significantly associated with SHD. However, age and duration of CPR were significantly associated to SHD, as 8-<18 yo had 85% lower odds of SHD than < 1 yo (aOR=0.15 {0.03, 0.73}; P=0.019) and every minute increase in duration of CPR decreased odds of survival by 4% (aOR=0.96 {0.94,0.99}; P=0.009). Conclusion: No SHD benefits were found among ECPR patients who received guideline-compliant CPR compared to patients who do not. Older patients and those with longer CPR duration had worse SHD outcomes irrespective of guideline-compliant CPR.