A 6 week-old boy whose mother and sister present with hereditary hemorrhagic telangiectasia (HHT) presented suddenly with listlessness, hypotonia, and acute anemia. Cerebrospinal fluid was grossly hemorrhagic. Brain CT scan was compatible with subarachnoid and intracerebral hemorrhage. Operative investigation diagnosed a ruptured aneurysm of one branch of the right middle cerebral artery. A large clot was removed from the right frontal lobe. The ruptured artery was clipped. Further cerebral and abdominal angiographies did not show other aneurysms. The infant died 18 days later, with bilateral subdural hematoma. The family history and review of the literature suggest that the rupture of a cerebral aneurysm in this infant may have been an early manifestation of HHT. Brain CT scan study seems mandatory in every infant born to a mother with HHT.