A gliosarcoma represents a biphasic tissue pattern with altering areas displaying glial and mesenchymal differentiation and accounts for approximately 2% of all glioblastomas. We present a rare case with rapid gliosarcomatous recurrence of the glioblastoma which have been taken a complete resection and concomitant chemoradiotheraphy (CCRT). A 54-year-old female presented with sudden onset of the headache. Magnetic resonance (MR) imaging showed a well-demarcated, enhanced lesion in the right fronto-temporal area. She received grossly total tumor resection followed by radiotherapy and chemotherapy. Her postoperative course was uneventful. However, brain MR images at 6 months after surgery demonstrated a newly developed, nodular lesion in the tumor bed. At 9 months after surgery, the follow-up MR images revealed the increased size of tumor in the right fronto-temporo-parietal area with invasion into the right lateral ventricle. She received surgery again, and pathological studies revealed a recurrent glioblastoma with the component of gliosarcoma. The authors report and discuss an uncommon case with gliosarcomatous recurrence of glioblastoma after surgery and CCRT.