In this study, we examined and treated 50 patients presenting with polypous rhinosinusitis. In all of them, the endoscopic surgical intervention was preceded by estimation of the olfactory function. The examination was repeated within 1, 3, and 6 months after the operation. Endoscopic surgery had positive outcome; however, its beneficial effect was compromised in the patients suffering from polypous rhinosinusitis during a long period and having the history of surgical intervention in the nasal cavity in the past. The best results of the treatment were obtained in the patients having olfactory dysfunction for less than 10 years and in the previously untreated ones. It is concluded that endoscopic rhinosurgical treatment produced positive results in all the 50 patients.