Background: Anterior (ACS) and posterior circulation (PCS) stroke patients have different clinical presentations and prognoses, though both benefit from endovascular thrombectomy (EVT). We sought to determine whether ACS and PCS patients treated with EVT differed with regards to treatment metrics and functional outcomes. Methods: We retrospectively analysed theCanadian OPTIMISE registry which included data from 20 comprehensive stroke centers across Canada between January 1, 2018, and December 31, 2022. We performed a descriptive analysis of patients divided in two groups (ACS= carotid artery and its branches, PCS= vertebrobasilar system). Results: Of the 6391 patients included (5929 ACS and 462 PCS), PSC patients were younger (67 vs. 71.3, p<0.001), more often male (61.9% vs. 48.6%, p<0.001), had longer (in minutes) onset-to-door (362 vs. 256, p<0.001), door-to-needle (172 vs. 144, p=0.0016), and onset-to-puncture (459 vs. 329, p<0.001) times. They were less often thrombolyzed (39.8% vs. 50.4%, p<0.001), and more frequently underwent general anesthesia (47.6% vs. 10.6%, p<0.001). Successful reperfusion and functional independence at 90 days were similar between the two groups. Conclusions: Patients with PCS had worst treatment metrics than ACS. Strategies to improve PCS management times are critical to decrease these disparities, including faster pre-hospital recognition and in-hospital workflows.