Anterior cerebral artery[ACA] dissecting aneurysms are extremely rare and optimal treatment remains unclear. The majority of cases manifest as cerebral infarction or as intracranial bleeding. The authors report two cases of ACA dissecting aneurysm, one with a large partially thrombosed gradually growing aneurysm and one with a cerebral infarction in the ACA territory. The patient with a large aneurysm was treated by trapping the aneurysm, and the patient with infarction by conservative management. We report on two cases of dissecting aneurysm of the ACA and include a review of pertinent literature.