The case of a boy with a familial history of Rendu-Osler disease, who successively developed a cerebellar pilocytic astrocytoma (at 3 years of age) and a metastatic supratentorial malignant rhabdoid tumor (at the age of 12 years) is reported. After a complete surgical removal, the CSF was cleared by 4 courses of chemotherapy, and the child received a craniospinal irradiation. He is currently alive and well 19 months after completion of the treatment. The authors discuss the ethiopathogeny of such intracranial tumors and argue for aggressive treatment.