목적: Though prevalent in both adults and children, chronic rhinosinusitis (CRS) is managed quite differently. Unlike adults, pediatric endoscopic sinus surgery (ESS) is performed only in medically refractory CRS patients. However, exact indications for surgery are debatable among specialists and causes of failure remain unclear. This study aimed to evaluate the surgical outcomes and prognostic factors, and suggest optimal indications for pediatric ESS. 방법:A retrospective cohort study was performed for pediatric chronic rhinosinusitis patients who had undergone surgical treatment at Seoul National University Children’s Hospital. Patients under the age of 18 who received ESS during 2016 and 2020 were selected. Control group was comprised of pediatric patients who visited the outpatient clinic during the same period for management of CRS. Demographics, endoscopic sinonasal findings, disease characteristics and computed tomography (CT) results were extracted for analysis. Recurrence rates and prognostic factors for surgery were determined. 결과:A total of 175 patients were enrolled in this study, 119 as a study group and 56 as a control group. Of those who received ESS, 65 patients (54.6%) showed significant improvement in symptoms with resolution of CRS. 29 patients (24.4%) showed recurrence of CRS and 3 patients required revision surgery. Multivariate logistic regression analysis revealed patients with higher preoperative Lund-Mackay score (OR=1.32, p=0.001) to show higher recurrence rates after surgery. Unlike prior reviews regarding prognostic factors of pediatric ESS, allergic rhinitis, nasal polyposis, blood eosinophilia or age did not display any valid predictive value in this study. 결론:Though there remains much debate of its efficacy, ESS can be effective in treating pediatric CRS. Multiple factors, including CT staging, polyposis, comorbidities and age, should be considered when proceeding to ESS. Among them, higher L-M score demonstrated as a poorer prognostic factor.