Clivus chordomas present a great challenge for neurosurgeons, and the prognosis is poor. To investigate bone invasiveness characteristics in regard to the prognosis of clivus chordomas, a retrospective study of 19 patients with primary clivus chordoma was performed. Clinical data, MRI, CT scans and follow-up data were examined, and the bone invasiveness of the chordoma was classified into two growth patterns (endophytic and exophytic) which were analyzed with regard to prognosis. The overall survival rate was 78.9% with radical surgery and adjuvant radiation, with a mean follow-up of 44.5 months. There were 12 patients in the endophytic group and seven in the exophytic group, and the exophytic group exhibited a higher recurrence rate than the endophytic group (p = 0.006). Chordomas with an exophytic growth pattern were more likely to recur than those with an endophytic growth pattern, and the surgical approach can be tailored according to each growth pattern. (C) 2015 Elsevier Ltd. All rights reserved.