Background: Previous research demonstrates that for acute ischemic stroke (AIS) cases, rapid endovascular therapy (EVT) performance improves outcomes. This study provides updated metrics summarizing estimates for modified Rankin Scale (mRS) gains accrued by streamlining time to EVT. Methods: A systematic review and meta-analysis (MA) was conducted using electronic databases. Eligible studies reported time-benefit slope with times from AIS onset (or time last-seen-normal) to EVT commencement; the predictor was onset-to-groin (OTG) time. Primary and secondary outcomes were 90-day functional independence (mRS 0-2) and 90-day excellent function (mRS 0-1), respectively. Results: The five included studies showed increased chance of good outcome with each hour of pre-EVT time savings for mRS 0-2 for 0-270’ (OR 1.25, 95% CI 1.16-1.35, I2 40%) and 271-360’ time frame (1.22, 95% CI 1.12-1.33, I2 58%). For studies assessing mRS 0-1, pooled effect estimates were appropriate for the 0-270’ time frame (OR 1.34, 95% CI 1.19-1.51, I2 27%) and the 271-360’ time frame (OR 1.20, 95% CI 1.03-1.38, I2 60%). Conclusions: Each hour saved from AIS onset to EVT start is associated with a 22-25% increased odds of functional independence, a useful metric to inform patient-specific and systems planning decisions.