Abstract Introduction: The effect of the quantity of olfactory neuroepithelium in the middle turbinate on the postoperative olfactory function for middle turbinate concha bullosa patients has not yet been evaluated. Objective: The primary aim of this study was to investigate the olfactory structures in the middle turbinate by immunohistochemical analysis of the olfactory marker protein and to correlate the immunostaining results with the olfaction test results for patients with middle turbinate concha bullosa. Methods: Surgical materials of 18 middle turbinate concha bullosa patients who had undergone lateral marsupialization surgery were immunostained with olfactory marker protein antibodies. Smell diskettes olfaction test was applied to all of the study group patients both preoperatively and three months postoperatively. A visual analog scale was used to quantify the sense of nasal obstruction. Results: It was observed that the postoperative smell scores and the nasal obstruction visual analog scale values were significantly improved as compared to the preoperative values (p<0.05). In addition, there was a significant correlation between the smell score gain and the visual analog scale gain values (r = 0.682). Results also indicated no significant correlation between the olfactory marker protein staining scores and the smell scores (p > 0.05). Conclusion: This first paper demonstrated that the quantity of the olfactory mucosa in the middle turbinate was not a determining factor for the postoperative smell function degree for middle turbinate concha bullosa patients. The underlying cause of the olfactory deficit for middle turbinate concha bullosa patients seems to be obstruction related rather than the middle turbinate’s olfactory mucosa containing status.