목적: Malignant sinonasal tumors are rare and aggressive cancers often presenting significant therapeutic challenges due to their proximity to critical anatomical structures. Endoscopic surgery has emerged as a promising alternative to traditional open approaches, but long-term survival and recurrence outcomes remain inadequately studied. This study aimed to evaluate the surgical outcomes, recurrence patterns, and survival rates of patients with sinonasal malignancies treated via endoscopic surgery over a 5-year period at a single tertiary care center. 방법:A retrospective review of 75 patients with malignant sinonasal tumors treated with surgery via endoscopic approach at Seoul National University Hospital between 2018 and 2023 was conducted. Medical records, endoscopic and radiologic images, and surgical videos were analyzed. Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier curves. Associations between patient factors and survival outcomes were assessed using Cox proportional hazards regression and Chi-square tests. 결과:The mean DFS was 45.8 months (95% confidence interval: 38.7–52.8 months) with a 5-year DFS rate of 50.8% (SE: ±9.3%). The mean OS was significantly longer at 125.6 months (95% confidence interval: 116.7– 134.6 months) with a 5-year OS rate of 92.2% (SE: ±3.8%). Revision surgeries had higher local recurrence rates (45.5%) than primary surgeries (25%) but demonstrated longer DFS, likely influenced by adjuvant treatments. Multivariate analysis revealed no statistically significant predictors of recurrence or death. Recurrence rates and DFS varied substantially among histological subtypes, while OS remained uniform. 결론:Endoscopic surgery for sinonasal malignancies demonstrates favorable overall survival outcomes but poses challenges in achieving disease- free survival, particularly in advanced-stage or recurrent cases. The findings highlight the importance of multidisciplinary approaches and adjuvant therapies to optimize outcomes. Further prospective, multi- center studies are warranted to validate these results.