PURPOSE: To elucidate the vessel wall changes of vertebrobasilar dolichoectasia (VBD) with ischemic stroke, using vessel wall magnetic resonance imaging (VW-MRI). METHOD: Thirty-four patients with VBD (22 with stroke and 12 without stroke) who underwent VW-MRI were recruited. Forty-one patients without VBD who underwent VW-MRI were also recruited if they had a recent stroke due to atherosclerosis in the basilar artery or the intracranial vertebral artery. The vessel wall features of VBD were compared between stroke and non-stroke groups. The plaque characteristics were compared between VBD and non-VBD stroke patients. RESULTS: The frequency of plaques was higher (54.5% vs. 8.3%, P = 0.011) in VBD patients with stroke than that in non-stroke patients, while the frequencies of aneurysm, dissection, intraluminal thrombus, and diffuse/concentric wall enhancement did not differ. When the plaque features were compared between plaque-positive stroke patients with and without VBD, the degree of stenosis (31.0% ± 26.8% vs. 71.5% ± 19.0%, P < 0.001), normalized wall index (NWI) (0.7 ± 0.1 vs. 0.9 ± 0.1, P < 0.001), and remodeling index (RI) (1.0 ± 0.4 vs. 1.3 ± 0.4, P = 0.023) were lower in the VBD group, while intraplaque hemorrhage, and enhancement ratio showed no difference. CONCLUSIONS: This preliminary study suggests that atherosclerosis may be an important cause of stroke in VBD patients. Symptomatic plaques in VBD patients have a lower degree of stenosis, NWI, and RI than that in non-VBD patients. VW-MRI may help to assess stroke mechanisms and identify VBD patients at high risk.