Introduction: A mucocele is an epithelial lined mucus-containing sac, completely filling paranasal sinus and capable of expansion.Sinus orifice obstruction produces aggregation of mucosal discharge from respiratory epithelium inside them that is called sinus mucocele.

Case Report: Present case-report is related to a case of concha bullosa mucocele in a 18-year-old girl presenting to the clinic due to partial obstruction of left-side nasal cavity over 8 months ago and then completed obstruction within the recent two months. The patient underwent surgical operation with a likely diagnosis of concha bullosa mucocele.

Conclusion: Pathologic study on the specimen taken during the surgery supported the mucocele. Post-operatively, no complication was detected. In a second examination within two months after the operation,the nasal cavity was open and no complication was found.