Case report of angiographic demonstration of persisting carotid-basilar anastomosis. It is the 7th case of such anomaly demonstrated by cerebral angiography and the 23rd of the totality of cases reported in the medical litterature. In this case, cerebral angiography was performed by injecting the contrast medium in both common carotid arteries and in the right vertebral artery. Persistence of carotid-basilar anastomosis causes intracranial hemodynamic changes which are discussed by the author based on the angiographic findings.