Churg-Strauss syndrome (CSS) represents a rare systemic vasculitis that is almost invariably accompanied by bronchial asthma and eosinophilia. We report a case of a 36-year-old woman with previously diagnosed CSS presented with subarachnoid hemorrhage (SAH) from dissecting aneurysm in a vertebral artery (VA). Two months before onset of SAH, the patient had presented with numbness on her right lower leg due to peripheral neuropathy. On admission, angiography revealed dissecting aneurysm of the right intracranial VA and stenosis of the basilar artery. Hematological examination revealed an increased percentage of eosinophils. Ruptured dissecting aneurysm of the intracranial VA was diagnosed. Emergent coil embolization of the dissecting aneurysm and occlusion of the parent artery was performed to prevent repeated hemorrhage from the dissecting aneurysm. Then pharmacotherapy with prednisone was initiated for CSS. The patient recovered well and was discharged without any neurological deficit. As far as we know, this is the first reported case of CSS presented with SAH from dissecting aneurysm on posterior circulation.