Pleomorphic xanthoastrocytoma is histologically characterized by marked cellular pleomorphism of lipid-laden neoplastic astrocytes and bizarre giant cells showing mitotic figures and high cellularity. Inspite of its ominous-looking microscopic features, howerver, the prognosis is usually favorable. This tumor develops mainly in the supratentorial area of young people and frequently involves the leptomeninges. We experienced a case of pleomorphic xanthoastrocytoma in 18 year-old-male. In addition to the cellular pleomophism, the prominent reticulin fibers surround the individual tumor cells or the tumor cells nests. Immunohistochemical staining and electron microscopy revealed glial fibrillary acidic protein(GFAP) expression and pericytoplasmic basal lamina in the tumor cells.