목적: Endoscopic sinus surgery (ESS) and septoplasty are commonly performed operations in otolaryngological practice. We can encounter the patients, who left hospital after sinonasal surgery, at the emergency room (ER). The aim of this study was to investigate the data of the patients who visited the ER and readmitted after the operation 방법:A total of 1805 patients who underwent ESS and/or septoplasty for ten years were enrolled in this study. We investigated the data of the patients who visited the ER and readmitted within 14 days after the operation 결과:Overall, 0.72% (13 patients) of 1805 patients had a visit the ER. The reasons of visit the ER were nasal bleeding, fever/sore throat, urination difficulty, eyelid swelling, and dizziness. Nasal bleeding was the most common reason for visit. Of 7 bleeding patients, three patients who had severe nasal bleeding were required bleeding control and blood transfusion. The nasal bleeding might not be related to the packing materials 결론:The most common reason for visit the ER was nasal bleeding. All patients should be warned prior leaving hospital after surgery that nasal bleeding can be occurred