BACKGROUND. Mucocele is a benign expansile cyst-like lesion seen in the paranasal sinuses, which has a tendency to expand and erode the surrounding sinus walls. These mucoceles develop as a result of obstruction of the sinus ostium and superadded infection. As such, the frontoethmoidal area is the most common site, followed by the maxillary sinus and the sphenoid sinus. Rarely, mucocele may also develop in abnormally aerated bones, such as middle turbinate (concha bullosa), clinoid process and pterygoid process.CASE REPORT. We report two infrequent cases of mucocele of concha bullosa, clinically presenting as the cause of nasal obstruction, which were completely removed endoscopically, and patients were symptomatically relieved.CONCLUSION. Mucocele of the middle turbinate represents a diagnostic challenge to surgeons both in terms of symptoms and risk of complications. Therefore, the condition should be considered as a possible cause of progressive nasal obstruction by otolaryngologists, and careful examination of the nasal cavity is necessary to determine the existence of this rare condition.