Surgical ciliated cyst is uncommon in Western countries but frequently reported in Asian populations as a delayed complication of surgery, with inclusion in the bone of nasal or sinus mucosa. Isolated cases have also been reported in the mandible after orthognathic surgery. We report a case in the maxillary region three years after radical sinus surgery for chronic sinusitis. Intraoral examination revealed a small painless tumefaction with no color change in the surrounding tissues. Computed tomography demonstrated a well-defined intraosseous lesion lateral to the maxillary sinus. The lesion was completely excised, when histology demonstrated a pseudostratified ciliated epithelial lining. Differential diagnosis from other lesions such as an odontogenic keratocyst or inflammatory cyst were also made. This case report,uncommon in Western countries, of a surgical ciliated cyst illustrates the need for a meticulous surgical technique, proper management of complications, and routine, long-term follow-up of patients undergoing any type of sinus surgery.