Functional endoscopic sinus surgery (FESS) is a common otolaryngologic procedure, with over 250,000 operations performed annually. Computerized surgical navigation systems are available to assist the rhinologic surgeon in the complex dissection required for FESS. Our objective was to determine whether this system provided quantifiable benefits in FESS. We retrospectively reviewed 203 patients with chronic sinusitis who underwent endoscopic sinus surgery, and divided them into two groups based on whether or riot computerized surgical navigation M,as used. There M,as no statistically significant difference between the two groups ill terms of surgery duration, extent of surgery percent of complementary procedures, percent of supplementary procedures, complexity of surgery, and percent revision surgery. Computer-assisted surgery (CAS) M,ns 6.7% more expensive than sinus surgery without computerized surgical navigation (p = 0.01). However, the intangible benefits of CAS may outweigh the added expense.