Objective 1) Learn the relative effectiveness of endoscopic sinus surgery (ESS) regarding improving individual major chronic rhinosinusitis (CRS) symptoms and headache. 2) Be able to more effectively counsel patients undergoing ESS. Methods A literature search of MEDLINE, EMBASE, Web of Science, Cochrane databases, and other Web-based sources from 1980–2008 was performed. Additional articles were identified by reviewing relevant bibliographies. Studies with more than 10 adult CRS patients that used symptom severity scores to analyze at least 4 major criteria (facial pressure, congestion, nasal obstruction, nasal discharge, and hyposmia/anosmia) or 3 major criteria as well as headache were included. 265 studies were identified and reviewed. 22 of these met inclusion criteria and their data were analyzed. After conversion of the symptom severity scores used in each study to a relative percent value, symptom categories were averaged, and compared in aggregate. Results This analysis included 1641 CRS patients (average of 74 pts/study). The patients were followed an average of 19.4 months (range, 1 week to 76 months) postoperatively. All 6 evaluated symptoms showed non-weighted, relative improvements in symptom scores. Overall, symptoms improved synchronously with a relative improvement over preoperative levels ranging from 27% to 36%. ESS provided the greatest relief from nasal obstruction (relative improvement of 36%), which was a significantly larger change than with facial pain (p<0.034) or nasal discharge (p<0.034). Conclusions The relative improvement in major CRS symptoms and headache after surgery is similar. Nasal obstruction improves slightly more than facial pain and nasal discharge.