Introduction: Atrial Fibrillation (AF) is the most common arrhythmia seen in patients presenting to the emergency department (ED). AF increases the risk of ischemic stroke which can be mitigated by anticoagulant prescription. National guidelines advise that emergency physicians initiate anticoagulation when AF is first diagnosed. We aimed to evaluate the 90-day incidence of stroke and major bleeding among emergency patients discharged home with a new diagnosis of AF. Methods: This was a health records review of patients diagnosed with AF in two EDs. We included patients ≥ age 18, with a new diagnosis of AF who were discharged from the ED, between 1st May 2014 and 1st May 2017. Using a structure review we collected data on CHADS65 and CHADS2 scores, contraindications to direct oral anticoagulant (DOAC) prescription and initiation of anticoagulation in the ED. Patient charts were reviewed for the diagnosis of stroke, transient ischemic attack (TIA), ischemic gut, ischemic limb or other systemic embolism within 90 days of the index ED presentation. We extracted data on major bleeding events within 90 days, defined by the International Society of Thrombosis and Haemostasis criteria. All data were extracted in duplicate for validation. Results: We identified 399 patients fulfilling the inclusion criteria, median age 68 (IQR 57-79), 213 (53%) male. 11 patients were already prescribed an anticoagulant for another indication and 19 had a contraindication to prescription of a DOAC. 48/299 (16%) CHADS65 positive patients were initiated on an anticoagulant, 3 of whom had a contra-indication to initiation of anticoagulation in the ED (1 dual antiplatelet therapy, 2 liver cirrhosis). 1/100 CHADS65 negative patients was initiated on anticoagulation. The median CHADS2 score was 1 (IQR 0-2). Among the 49 patients initiated on anticoagulation, 3 patients had a stroke/TIA within 90 days, 6.1% (95% CI; 2.1-16.5%). There were no bleeding events 0.0% (95% CI; 0.0-7.3%). Among the 350 patients who were not initiated on anticoagulation in the ED, 4 patients had a stroke/TIA 1.1% (95% CI; 1.1-2.9%) within 90 days and 2 patients had a major bleeding event. Conclusion: Prescription of anticoagulation for new diagnoses of AF was under-utilized in these EDs. The 90-day stroke/TIA rate was high, even among those given an anticoagulant prescription in the ED. No patient had an anticoagulant-associated bleeding event.