Background <p>Post-orthognathic surgical ciliated cyst (POSCC) is a benign, acquired cystic lesion associated with a history of orthognathic surgery, maxillofacial trauma, and similar events. This study presents a case of a maxillary POSCC that developed five years after a Le Fort I advancement osteotomy.</p> Case presentation <p>A 25-year-old male patient developed a painless, gradually fluctuant swelling in the anterior maxillary area following previous surgical treatment. Radiographic investigations revealed a unilocular radiolucent lesion from the left to right premolars, encompassing the apices of the teeth with a scalloped border. With clinicopathological correlation and consideration of the patient’s history, the diagnosis of surgical ciliated cyst was confirmed. Decompression followed by lesion excision was performed for the patient. A one year follow-up showed no recurrence or complications.</p> Conclusion <p>Although POSCC is a rare complication following surgery involving the maxillary bone and sinus, it can lead to large lesions with extensive growth. Long-term radiographic follow up is highly recommended after Le Fort osteotomy.</p>