Background Angiographic reperfusion after endovascular thrombectomy in acute ischemic stroke is commonly graded using volume-based reperfusion scores such as the modified thrombolysis in cerebral infarct score. The location of non-reperfused regions is not included in modified thrombolysis in cerebral infarct score. We studied the predictive ability of an eloquence-based reperfusion score. Methods Consecutive cases of endovascular thrombectomy for anterior circulation strokes performed between January 2018 and April 2020 were included. Digital subtraction angiograms were reviewed by two blinded neurointerventionalist operators. Incomplete reperfusion was further classified by lobar regions lacking reperfusion to create various cohorts. Outcomes were graded four to seven days post-procedure with the National Institute of Health Stroke Scale (NIHSS) and 90 days post-procedure with the modified Rankin Scale. Results One hundred patients were identified. Via multivariate analysis, we found that frontal lobe non-reperfusion (mean difference (MD) = −1.60, p = 0.002) and occipital lobe non-reperfusion (MD = −1.68, p = 0.001) were associated with worse mental status improvement while left-sided stroke (MD = 2.02, p < 0.001) featured better improvement post-thrombectomy. Occipital lobe non-reperfusion (MD = −0.734, p = 0.009) was associated with the worse improvement of visual fields. The non-reperfusion of the frontal lobe was associated with a 1.732-worse NIHSS hemibody strength score (95% confidence interval (95%CI) = −3.39 to −0.072, p = 0.041). Worse improvement in NIHSS scores was found to be associated with frontal lobe non-reperfusion (MD = −5.34, 95%CI = −9.52 to −1.18, p = 0.013) and occipital lobe non-reperfusion (MD = −6.35, 95%CI = −10.4 to −2.31, p = 0.002). Odds of achieving modified Rankin Scale of 0–2 at 90 days were decreased with frontal lobe non-reperfusion (odds ratio (OR) = 0.279, 95%CI = 0.090–0.869, p = 0.028) and left laterality (OR = 0.376, 95%CI = 0.153–0.922, p = 0.033). Conclusions Eloquence-based reperfusion assessment is an important predictor for functional outcomes after thrombectomy.