Aneurysm of the anterior inferior cerebellar artery (AICA) is a very rare entity and the manifestation and manipulation of such aneurysms remain contentious. In this paper, we report a case where a successful surgery for an olfactory groove meningioma was performed and the patient discharged but readmitted to hospital with loss of consciousness and subsequently passed away three hours after re-admission. The patient was diagnosed with subarachnoid hemorrhage. The cause of the fatal subarachnoid hemorrhage was rupture of a new onsetting AICA dissecting aneurysm which had provided neither clinical nor radiological signs before the operation. We discuss the possible causes of the formation of such aneurysm.