Background: Emergency Medical Services (EMS) transport facilitates rapid ischemic stroke treatment. We hypothesized that EMS stroke recognition is critical to delivery of optimal stroke care and favorably impacts downstream outcomes. Methods: We identified consecutive EMS-transported ischemic stroke (IS) and transient ischemic attack (TIA) patients at 4 primary stroke center hospitals over a 2-year period. Cases were categorized as EMS recognized or unrecognized based on documented EMS impression. Compliance with EMS performance measures (stroke screen use, onset time documentation, prenotification), hospital-based measures (door-to-CT [DTCT] times, t-PA delivery), and hospital discharge disposition were compared among EMS recognized and unrecognized cases. Logistic regression was used to adjust for confounders such as age, gender, stroke severity, and clustering by agency or hospital. Results: EMS transported 1,056 IS/TIA patients during the study period; 719 (68%) were recognized and 337 (32%) unrecognized. EMS recognized cases were more likely to receive recommended prehospital care, early CT, and t-PA (Table). EMS recognized cases also had higher odds of being discharged home and lower odds of death in adjusted analysis. Conclusion: EMS recognition of IS/TIA was associated with prehospital quality measure compliance, faster ED evaluations, t-PA delivery, and superior outcomes. Quality improvement efforts should focus on improving EMS stroke recognition.