Nasal endoscope has been used increasingly during skull base surgery. However, most of endoscopic surgery limited to the repair of cerebrospinal rhinorrhea, decompression of traumatic optic nerve, hypophysectomy, etc. This study was undertaken to determine whether endoscopic endonasal approach was safe and effective for the resection of tumors located in petroclival region and infratemporal fossa. Seventeen patients with tumors of petroclival region and infratemporal fossa treated by endoscopic endonasal surgery between January 2002 and February 2005 were studied prospectively. The operative technique was described in detail. There were 5 chordoma, 1 esthesioneuroblastoma, 1 chondrosarcoma, 1 lymphoma, 1 craniopharyngioma, 1 hemangioblastoma, 4 meningioma, 1 schwannoma, and 2 metastatic carcinoma. 3 patients were selected for neuronavigation-aided endoscopic endonasal surgery. Total tumor removal was obtained in 15 cases, subtotal removal in 2 case. With follow-up of 5 to 43 months, 1 case with chordoma was recurrent 5 months later postoperatively and underwent reoperation subsequently. The other cases with benign tumors were no recurrence. All of 5 cases with malignant tumors followed up for longer than 2 years were no recurrence and death. The complications included subarachnoid hemorrhage in 1 patient, transient cerebrospinal leakage in 2 cases. The endoscopic endonasal surgery provides satisfied treatment for selected tumors of petroclival region and infratemporal fossa. This approach promises a simple and rapid access to petroclival region and infratemporal fossa. It is a safe, minimally invasive and efficient procedure. Using neuronavigation system, it is helpful to determining anatomical landmark and removing the tumor completely and securely.