The aim of this study is to investigate the efficacy and safety of preoperative versus intraoperative tirofiban in patients with large vessel occlusion (LVO) due to large artery atherosclerosis (LAA). This is a retrospective multicenter cohort study based on the RESCUE-RE (Registration Study for Critical Care of Acute Ischemic Stroke After Recanalization) trial enrolling patients with anterior circulation LVO classified as LAA within 24 h of onset. Patients were divided into three groups: preoperative tirofiban (PT), intraoperative tirofiban (IT), and no tirofiban (NT). Propensity score matching (PSM) was used to balance baseline characteristics. The efficacy outcomes included 90-day functional independence (modified Rankin Scale score = 0-2) and early partial recanalization (EPR; defined as a modified Thrombolysis in Cerebral Infarction score = 1-2a). The safety outcomes included symptomatic intracranial hemorrhage (sICH). A total of 104 matched triplets were obtained through PSM. Compared with NT, PT increased 90-day functional independence (60.8% vs. 42.3%, p = 0.008) and EPR (42.7% vs. 18.3%, p < 0.001) rate, with a tendency to increase the asymptomatic intracranial hemorrhage (aICH) proportion (28.8% vs. 18.3%, p = 0.072). Compared with IT, PT had a higher 90-day functional independence (60.8% vs. 45.2%, p = 0.025) and EPR (42.7% vs. 20.2%, p = 0.001) rate, with no significant difference in sICH (14.4% vs. 7.7%, p = 0.122) and aICH (28.8% vs. 21.2%, p = 0.200). Compared with NT, IT had a lower 90-day mortality rate (9.6% vs. 24.0%, p = 0.005). Tirofiban shows good adjuvant therapy potential in acute ischemic stroke-LVO due to LAA patients. PT is associated with higher rates of EPR and better therapeutic efficacy. In addition, EPR may be a potential way to improve prognosis.