Background: RSV infection poses a threat of severe lower respiratory tract illness in children. We investigated RSV-related ICU admissions and risk factors among Korean children. Methods: A retrospective study using EMR transformed into OMOP CDM was conducted across three Korean tertiary centers from 2008 to 2022. Pediatric patients hospitalized with RSV infection were analyzed to identify ICU admission risks. Results: Among 33,674 children aged 0–9 years tested, 4.5% were RSV positive, peaking in <10-month-olds. Of 1,529 RSV-positive cases, 29 required ICU, mainly <5 months. Logistic regression showed varying ICU admission odds across age groups. Gestational age < 27 weeks and extremely low birth weight had notably higher odds, with 28–36 weeks’ gestation and LBW also significant. Conclusion: This study, utilizing OMOP CDM, uncovers critical risk factors for severe RSV infection in children. Future multi-institutional research can enhance our understanding of these factors.