The study objective was to investigate the relations between serum endothelin-1 and in-stent restenosis in vertebral artery stenting. Sixty-eight patients undergoing re-examination of vertebral artery stenting in the Department of Cerebrovascular Disease, Hangzhou Third People’s Hospital, between April 2019 and October 2022, were invited to participate. According to the presence of vertebral artery stenting, patients were divided into the restenosis (n = 19) or non-restenosis (n = 49) groups. General clinical data and endothelin-1 levels were compared between the groups. Logistic regression analysis was used to explore the relations between endothelin-1 level and risk for in-stent restenosis. Receiver operating characteristic curves were drawn to test the diagnostic value of serum endothelin-1 level for in-stent restenosis. Compared with the non-restenosis group, restenosis group levels of low-density lipoprotein, triglycerides, and endothelin-1 were significantly higher (p < 0.05) Multivariate logistic regression analysis showed that endothelin-1, stent length, and low-density lipoprotein were independently associated with in-stent restenosis (odds ratio = 1.502, 95% confidence interval: 0.042 ~ 0.212, p = 0.000; odds ratio = 1.899, 95% confidence interval: 1.116 ~ 2.237, p = 0.000; odds ratio = 1.899, 95% confidence interval: 1.228 ~ 3.337, p = 0.001, respectively). Area under the curve for serum endothelin-1 in the diagnosis of vertebral artery in-stent restenosis was 0.938. The best diagnostic cut-off value was 11.94 ng/L. Sensitivity was 89.5%. Specificity was 85.7%. These cumulative data indicate that endothelin-1 level is independently associated with in-stent restenosis.