Introduction: Observational study data suggest that statin pretreatment (SP) could be associated with better outcomes in acute ischemic stroke (AIS) by improving collateral circulation. In turn, adequacy of collateral circulation is known to improve neurological outcome through the reduction of final infarct volume (FIV) after an AIS. We sought to evaluate the association of SP on collateral circulation status and FIV in patients with AIS due to large vessel occlusion. Methods: We performed a systematic review and meta-analysis on MEDLINE and SCOPUS databases to identify all studies reporting on collateral circulation status and/or FIV, according to SP history. We contacted authors of eligible for inclusion studies to provide data of interest, in case they were not available in original publications. Good collateral status was defined on angiography by scores 3-4 according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grading system or collateral pial circulation scores of 0-2. In eligible studies we also estimated the standardized mean differences (SMDs) on the FIV measurements according to SP history. All analyses were performed under the random-effects model, while heterogeneity was assessed with the I 2 and Cochran Q statistic. Results: We identified 8 eligible study protocols (972 AIS patients; 32% with SP history). Patients with history of SP had significantly lower FIV (SMD=0.21, 95%CI: 0.01-0.41, p=0.04; Figure A) compared to the rest. Moreover, SP tended to be associated with good collateral status (odds ratio=1.45, 95%CI: 0.92-2.29, p=0.11; Figure B) compared to patients without SP history. No evidence of heterogeneity (I 2 <35%) was detected in both analyses. Conclusion: SP appears to be associated with decreased FIV after AIS, possibly due to more favorable collateral circulation. This observation deserves further validation in large-scale, prospective cohort studies.