This study was performed to review the experience of 3 patients with sinonasal inverted papilloma who underwent transnasal endoscopic medial maxillectomy. The average operative time was 1 hour 38 minutes and the average blood loss was 123ml. There was no recurrence with average follow-up of 28.7 months. I discuss the management of the medial wall of the maxillary sinus during resection of the tumor. Transnasal endoscopic medial maxillectomy is an effective technique for inverted papilloma with extension to the maxillary sinus.