The persistence of embryonic carotid‐basilar and carotid‐vertebral anastomoses was investigated retrospectively in 4,400 cerebral angiograms. Six primitive persistent carotid‐basilar anastomoses and one primitive persistent carotid‐vertebral anastomosis were found. In 4,400 cerebral angiograms, the incidence of primitive carotid‐basilar and carotid‐vertebral anastomoses was 0.14% and 0.023% respectively. Primitive persistent anastomoses are associated with intracranial vascular anomalies, especially aneurysms. The clinical and pathological findings in combination with these primitive persistentanastomoses were also examined. © 1995 WiIey‐Liss, Inc. Copyright © 1995 Wiley‐Liss, Inc.