A 12-year-old Japanese girl with a primary intracranial choriocarcinoma arising from the pituitary fossa is reported. There was a markedly high level of serum human chorionic gonadotropin (HCG) throughout the clinical course. Postmortem examination revealed metastatic lesions found in the cerebellum, dura mater, skull (clivus, sphenoidal bone), and lungs. Immunohistochemical characteristics of the primary intracranial tumor and lung lesions disclosed positive stainings for HCG and HCG-beta in the neoplastic syncytiotrophoblastic cells.