Background: Skull base chordomas are challenging and have a high rate of recurrence. Methods: A modified anterior transpetrous approach (ATPA) was performed in 17 upper clivus chordomas, and clinical data were retrospectively studied. Results: All 17 cases were radically treated via the modified ATPA, and the total removal and subtotal removal rates were 23.5% and 76.5%, respectively. The primary complaints were headaches and visual disturbances. The short-term postoperative complications were diplopia (12 cases, 70.6%) and facial numbness (7 cases, 41.2%). With a mean follow up of 44.5 months, 5 cases (29.4%) presented with tumor recurrence, and most cases had relatively good outcomes except for 2 patients who died because of rapid recurrence. The long-term complications were facial numbness (35.3%). Conclusions: The upper skull base chordomas could be radically removed via the modified ATPA under selected conditions, with limited complications and improved outcomes. The radical surgery treatment strategy was recommended for skull base chordomas. However, the present series included limited cases; therefore, post-operative follow-up, long-term outcomes and a larger number of cases of clivus chordomas should be observed to evaluate the effectiveness of the modified ATPA approach. (C) 2014 Elsevier B.V. All rights reserved.