The aim of the study is to explore the indications for cardiac catheterization while on extracorporeal membrane oxygenation (ECMO) and the various catheter interventions performed as well as assess the safety profile and determine the short- and intermediate-term survival. ECMO is a lifesaving intervention for pediatric patients with respiratory and/or cardiovascular failure. There is limited recent literature discussing the survival and outcomes of patients undergoing cardiac catheterization while on ECMO. A retrospective review of consecutive patients undergoing catheterization while on ECMO from 2004 to 2013 was performed. Thirty-six patients who underwent 40 cardiac catheterizations were identified. Indications for catheterization included hemodynamic/anatomic assessment of postoperative (16) and non-operative patients (7), planned catheter interventions (CI) (12), and cardiomyopathy assessment (5). CI were performed during 18 (45 %) catheterizations, including stenting of vessels/surgical shunts (9), balloon atrial septostomy (4), device closure of septal defects/vessels (3), thrombolysis of vessels (2), endomyocardial biopsy (2), and temporary pacer wire placement (1). Unexpected diagnostic information was found in 21 (52 %), and 13 patients were referred for surgical intervention. Successful decannulation was achieved in 86 % of patients. Survival to discharge was 72 % and intermediate survival was 69 % (median = 29 months). Survival was 88 % (15/17) among patients who underwent CI. There were six procedural complications (15 %); five vascular and one non-vascular. There were no complications related to patient transport. Cardiac catheterization and interventions while on ECMO are safe, with a survival to discharge of 72 %. Diagnostic information obtained from catheterization leads to management decisions which may impact survival.