Extracorporeal membrane oxygenation (ECMO) can provide an option for high-risk procedures that may result in cardiopulmonary collapse. The indications for ECMO standby are not well delineated. We describe the experiences of pediatric ECMO standby at two high-volume centers. A retrospective review of pediatric ECMO standby from 2016 to 2023 was performed (n = 394). Data regarding the locations of ECMO standby and the types of procedures were obtained. The primary outcome evaluated was requiring ECMO cannulation during standby. Of the 394 pediatric patients, only 8 (2%) required ECMO cannulation during standby. The indications for ECMO standby were cardiac (84%) and respiratory (16%) complications. Standby locations included the cardiac catheterization suite (55.6%), the operating room (OR) (20.6%), the intensive care unit (ICU) (11.9%), and the interventional radiology (IR) suite (11.9%). Standby within the cardiac catheterization suite included diagnostic only (53%) and interventional (47%), of which 0 and 4 (3.9%) patients required ECMO, respectively. Procedures in OR, IR, or ICU consisted of major surgical procedures (14%), minimally invasive minor procedures (64%), intubations (18%), and transfers/births (4%). Few ECMO standby patients require cannulation; however, it is complicated to predict patient decompensation. Further studies are warranted to delineate which patients would benefit from ECMO standby while balancing cost and resource utilization.