Carotid artery stenosis is the major cause of stroke. Carotid artery stenting (CAS) is the less invasive treatment for this condition. But, the tortuosity of aortic arch or carotid bifurcation are considered a risk factor for CAS. The authors evaluated the impact of catheter access route on outcomes. A retrospective study was conducted on patients with CAS from 2015 to 2020. Accessed anatomical factors were acute angle type of aortic arch and carotid artery angulation. The outcomes were set as symptomatic stroke within 30 days postoperatively and postoperative ischemic diffusion-weighted imaging (DWI) lesions. In this study, 157 cases were included. In bivariate analysis, left-sided lesions and symptomatic stroke (p = 0.028), as well as age and ischemic DWI lesions (p = 0.004), were associated. On the other hand, two anatomic factors did not affect post-treatment outcomes in bivariate analysis. Safe treatment can be expected by preoperative evaluation of vascular anatomy.