To assess objective and quality of life (QOL) outcomes before and after endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis (CRS) and to determine preoperative factors that predict surgical outcome in these patients. One hundred nineteen adult patients with CRS and a mean follow-up of 1.4 +/- 0.35 years were evaluated prospectively including the following patient factors: prior sinus surgery, polyps, asthma, acetylsalicylic acid intolerance (ASA), smoking, allergy, depression, and sex. Computed tomography (CT), endoscopy, and QOL assessment was performed. Predictive value of patient factors was determined based on change in endoscopy and QOL scores after ESS. Objective outcomes: preoperative CT scores were significantly worse in patients with polyps, asthma, and ASA, whereas CT score was unaffected by prior sinus surgery, smoking, allergy, depression, and sex. Patients with CRS demonstrated significant improvement on nasal endoscopy after ESS, but preoperative, postoperative, and change in scores were affected by certain patient factors. Endoscopy scores were significantly worse in patients with prior sinus surgery, polyps, asthma, and ASA, but these patients also experienced the greatest improvement in endoscopy scores. Smokers and patients with depression had the least change in endoscopy scores. QOL outcomes: patients with CRS experienced improvement in QOL after ESS. Pre- and postoperative QOL was positively affected by polyps and adversely affected by ASA, depression, and female sex, but these groups still experienced significant improvement in QOL scores. Pre- and postoperative QOL was unaffected by prior sinus surgery, asthma, smoking, and allergies, and all of these groups experienced significant improvement in QOL scores. Factors predictive of outcome: ASA and depression were predictive of worse outcome. Preoperative CT scores approached significance as being predictive of outcome. Surgical management of CRS was associated with significant improvement on objective and QOL measures; however, specific patient factors, in particular ASA and depression, predict poorer outcome. Preoperative CT may be a predictor of endoscopic and QOL outcome and deserves further study.