In-hospital arrests are uncommon in pediatrics, making it difficult to identify the risk factors for unrecognized deterioration and to determine the effectiveness of rapid response systems. An emergency transfer (ET) is a transfer from an acute care floor to an intensive care unit (ICU) where the patient received intubation, inotropes, or ≥3 fluid boluses in the first hour after arrival or before transfer. Improvement science work has reduced ETs, but ETs have not been validated against important health outcomes. This case-control study aimed to determine the predictive validity of an ET for outcomes in a free-standing children's hospital. Controls were matched in terms of age, hospital unit, and time of year. Patients who experienced an ET had a significantly higher likelihood of in-hospital mortality (22% vs 9%), longer ICU length of stay (4.9 vs 2.2 days), and longer posttransfer length of stay (26.4 vs 14.7 days) compared with controls (P < .03 for each).