Purpose : The vertebral artery dissection is rare and increasingly recognized as a source of stroke. Thepurpose of this study is to describe causes, clinical manifestations, MRI and angiographic findings. Materials and Methods : Conventional angiograms(n=7) and magnetic resonance imaging(n=6) were retrospectively analyzed in sevenpatients of vertebral artery dissection. The classification of the Krayenbuhl and Yasargil for vertebral arterysegmentation was used for localization of vertebral artery dissection. Additionally, etiology and clinicalmanifestations were also retrospectively reviewed. Results : Six cases were spontaneous type and one case wastraumatic type. The clinical diagnoses of 6 spontaneous arterial dissection cases were wallenberg syndrome(4cases), subarachnoid hemorrhage(1 case), and infarction of the cerebellum corresponding to PICA territory(1 case). A linear bright signal caused by thrombus was well visualized at the dissection area on sagittal T1 weighted spinecho MR images in all 6 cases. The characteristic angiographic findings were profound narrowing in 4 cases, pearland string sign(including dissecting aneurysm) in 3 cases, complete obstruction in 3 cases, and a double densitylumen(true and false lumen) extended to proximal basilar artery in one case. Spontaneous dissections were locatedat the V4 segment in all 6 cases. One traumatic dissection was located at the V2 segment. Conclusion : The mostcommon site of the spontaneous dissection of the vertebral artery was V4 portion and a linear bright signal causedby thrombus was well visualized on sagittal T1 weighted spin echo MR images.