The objective of this study was to compare clinical outcomes in patients who with unfavorable vascular anatomy underwent mechanical thrombectomy (MT) by common carotid artery access versus transfemoral approach.A retrospective review was performed in our hospital database to identify patients with challenging vascular anatomy who underwent MT for anterior circulation large vessel occlusion (LVO) between August 2015 and November 2018. Transcarotid and transfemoral cohorts were compared. Patient characteristics, procedural techniques, clinical outcomes were recorded.A total of 52 patients were included, 16 (31%) underwent MT via transcarotid access. There were no significant differences in patient characteristics, intravenously recombinant tissue plasminogen activator therapy, clot location, or carotid tortuosity and presence of aortic arch type. There were significant differences in clinical outcomes between the 2 cohorts, including mean access-to-reperfusion time (84 vs 44 minutes; P = .000), poor clinical outcome (modified Rankin scale >2) at 90 days follow-up (37.5% vs 63.9%; P = .034). But there were no significant differences in successful revascularization rates (thrombolysis in cerebral infarction score ≥2b 87.5% vs 80.6%; P = .541), post-thrombectomy symptomatic intracranial hemorrhage (12.5% vs 13.9%; P = .892), and mortality (12.5% vs 22.2%; P = .412) were similar between transcarotid and transfemoral cohorts.Our results demonstrate that transcarotid access for MT of anterior circulation LVO in patients with unfavorable vascular anatomy may be considerable. Transcarotid access may be better than transfemoral access in well-selected unfavorable vascular anatomy patients undergoing MT.