Aim To study vertebral artery stenosis and its relationship with posterior circulation cerebral infarction after vertebral artery stenting (VAS), and to explore the risk factors of posterior circulation cerebral infarction. Methods Volume computed tomographic digital subtraction angiography (VCTDSA) was used to evaluate the vertebral artery stenosis in 134 patients with posterior circulation ischemia (PCI) after VAS. The patients were divided into two groups:45 cases in PCI symptom with vertebral artery stenosis group (PCI-V group) and 89 cases in simple PCI symptom group (PCI group). The correlation between vertebral artery stenosis and posterior circulation cerebral infarction was analyzed statistically, and the risk factors of posterior circulation cerebral infarction after VAS were analyzed by univariate analysis and multivariate analysis. Results In PCI-V group, there were 51 vertebral artery stenosis sites with an average stenosis rate of (82.1%±6.7%), including 6 cases of mild stenosis, 13 cases of moderate stenosis, 20 cases of severe stenosis and 6 cases of complete occlusion. There was significant difference in the incidence of posterior circulation cerebral infarction between PCI-V group and PCI group (χ²＝10.600, P＝0.001). The incidences of posterior circulation cerebral infarction of patients with moderate stenosis, severe stenosis and complete occlusion in PCI-V group were significantly higher than that of patients in PCI group (all P＜0.05). The results of univariate analysis showed that NIHSS score≥12, hyperhomocysteinemia and diabetes history were the risk factors for posterior circulation cerebral infarction in PCI-V patients. Logistic multivariate analysis showed that NIHSS score≥12, hyperhomocysteinemia and diabetes history were independent risk factors for posterior circulation cerebral infarction in PCI-V patients. Conclusions Posterior circulation cerebral infarction after VAS is related to vertebral artery stenosis. NIHSS score≥12, hyperhomocysteinemia and diabetes history are independent risk factors of posterior circulation cerebral infarction in patients with PCI and vertebral artery stenosis after VAS.