Nasal surgery is frequently performed. Predictors of surgical outcome in terms of chemosensory function are not clear. A total of 64 patients were included in this prospective study (41 men, 23 women; age range 22-67 years). Prior to surgery, patients received a detailed otorhinolaryngological examination including nasal endoscopy, and CT scans used to establish the Lund-Mackay score. Olfactory function was analyzed using a custom-built odor identification test which allowed separation of chemosensory function into "olfactory" and "trigeminal" portions. Retest was performed 6 months after surgery. In terms of the sense of smell, nasal surgery produced the highest success rates in women, high degree of polyposis, and aspirin-intolerance. Neither age, presence of asthma, nor the number of preoperative surgical interventions had a significant impact on the outcome of surgery in terms of chemosensory function. Although "trigeminal scores" changed to a lesser degree than "olfactory scores", the present results indicated that nasal surgery may also improve trigeminal function, although this needs further corroboration. Improvement of olfactory function following nasal surgery appears to last, on average, for at least 6 months. While the present results may be seen as an encouraging step towards the description of more detailed prognostic factors related to nasal surgery, results from the present investigation also point towards the idea that nasal polyposis is due to a multifactorial process that, so far, is not adequately addressed by current research. Future work is needed to identify further predictors of postoperative outcome in terms of olfactory function.