Pleomorphic xanthoastrocytoma (PXA) is a type of astrocytic neoplasm, classified as WHO grade II, which mainly occurs supratentorially, and rarely infratentorially. We report an unusual case of PXA in the cerebellar vermis. A 36-year-old man presented with headache and gait disturbance. Magnetic resonance imaging and computed tomography demonstrated a mass lesion with cyst in the cerebellar vermis. The patient underwent total resection. Histological examination demonstrated nuclear and cytoplasmic pleomorphism, and xanthomatous change. Immunohistochemical examination demonstrated xanthomatous cells expressing glial fibrillary acidic protein. The histological diagnosis was PXA of the cerebellar vermis. The patient did not receive radiation therapy or chemotherapy after resection, and has experienced no recurrence for 12 months. This case suggests that PXA should be considered in the differential diagnosis of cystic lesion in the cerebellar vermis.