Conclusion. Extensive inverted papilloma (Krouse T3 lesions) with attachment to the frontal sinus drainage pathway can be treated successfully using an endoscopic approach. Objectives. The endoscopic management of inverted papilloma (IP) has gained in popularity over the last 15 years. However, the appropriate management of lesions involving the frontal sinus and its drainage pathway still has to be determined. Patients and methods. We performed a retrospective review of the results for patients with IP in the Otolaryngology, Head and Neck Surgery Department, Beijing Tongren Hospital from 2004 to 2007 to identify those patients with lesions involving the frontal sinus and its drainage pathway. By their appearance on nasal endoscopic examination and by computed tomography scanning, the tumors were defined using the Krouse staging system. Sinus endoscopy was used to screen for disease after endoscopic resection and the clinical outcomes were analyzed. Results. A total of nine patients (eight males and one female) were identified in which IP involved the frontal sinus and its drainage pathway. Preoperative and postoperative pathological examinations revealed IP as the diagnosis. All tumors were defined as T3 lesions. Four cases with lateral wall of frontal recess tumor attachment underwent an endoscopic Draf IIA frontal sinusotomy. Three cases with either lateral and posterior walls of frontal recess and frontal infundibulum attachment, or medial and posterior walls of frontal recess and frontal infundibulum attachment underwent a Draf IIB procedure. Two cases with posterior wall of frontal recess and frontal infundibulum attachment, or medial, lateral, and posterior walls of frontal recess and frontal infundibulum attachment underwent a Draf III procedure. All patients remain disease-free after an average follow-up period of 15 months.