Background and Purpose— In acute ischemic stroke patients treated by intravenous thrombolysis, a diffusion-weighted imaging (DWI) Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is an independent factor of functional outcomes. Our aim was to assess the impact of pretreatment DWI-ASPECTS on outcomes after endovascular therapy, with a specific emphasis on recanalization. Methods— We analyzed data collected between April 2007 and March 2013 in a prospective clinical registry of acute ischemic stroke patients treated by endovascular approach. Every patient with a documented internal carotid artery or middle cerebral artery occlusion who underwent an acute DWI-MRI before treatment was eligible for this study. The primary outcome was a favorable outcome defined by modified Rankin Scale of 0 to 2 at 90 days. Results— Two hundred ten patients were included and median DWI-ASPECTS was 7 (interquartile range, 4–8). DWI-ASPECTS ≥5 was the optimal threshold to predict a favorable outcome (area under the curve=0.69; sensitivity, 90%; specificity, 38%). In a multivariate analysis including confounding variables, the adjusted odds ratio for favorable outcomes associated with a DWI-ASPECTS of ≥5 was 5.06 (95% confidence interval, 1.86–13.77; P =0.002). Nonetheless, the occurrence of a complete recanalization was associated with an increased rate of favorable outcomes in patients with DWI-ASPECTS under 5 (50% versus 3%, P <0.001). Conclusions— DWI-ASPECTS ≥5 seems to be the optimal threshold to predict favorable outcomes among patients undergoing endovascular reperfusion within 6 hours. Selected patients with a DWI-ASPECTS of <5 may still benefit when a complete reperfusion is achieved.