BACKGROUND:Exposure to cigarette smoke has been associated with a higher incidence of postoperative complications across a variety of surgical specialties. However, it is unclear if smoking increases this risk after endoscopic sinus surgery (ESS). Because complication rates after ESS are relatively low, a large national database allows for a statistically meaningful study of this topic. METHODS:The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) dataset from 2005 to 2016 was analyzed. Patients who underwent ESS were identified. Thirty-day postoperative complication rates between smokers and nonsmokers were compared. Complications included infection, thromboembolic events, reintubation, readmission, acute renal failure, and cardiovascular events. RESULTS:921 patients who underwent ESS were identified. 182 (20%) were smokers and 739 (80%) were nonsmokers. 609 patients underwent outpatient ESS, while 312 patients underwent inpatient ESS. A total of 12 patients experienced postoperative surgical site infections involving the deeper tissues beyond the wound (organ/space SSI). On univariate analysis, smoking was associated with a higher incidence of organ/space SSI (P = .0067) and pulmonary embolism (P = .0321) after ESS. On multivariate logistic regression, smoking was associated with increased odds (4.495, 1.11- 8.17, P = .0347) of organ/space SSI after ESS. CONCLUSIONS:This study demonstrates an association between exposure to cigarette smoke and potentially serious surgical site infections in the 30-day postoperative period after ESS. Our findings may help when counseling smokers who are considering ESS. Further study is required to understand the nature of these infections and ways to prevent them.Level of Evidence: 2c ("health outcomes").