Introduction: Acute atrial fibrillation or flutter (AFF) is the most common dysrhythmia managed in the emergency department (ED). A key component of managing AFF in the ED is the prevention of stroke. Predictive indices (e.g., CHADS2 , HAS-BLED) should be used to assess each patient’s risk of stroke and bleeding to determine the appropriate anticoagulation therapy. The frequency of use of these predictive indices in the emergency department to determine appropriate anticoagulation therapy remains unclear. This systematic review is designed to examine the use of risk scores in the ED to determine the management of patients presenting to the ED for atrial fibrillation and flutter. Methods: An extensive search of eight electronic databases and grey literature was conducted. Quasi-experimental studies were eligible for inclusion. Studies had to report on the ED management of adult patients presenting with AFF to be included. Two independent reviewers judged the relevance, inclusion, and risk of bias of the studies. Individual and pooled statistics were calculated as odds ratios (OR) with 95% CI using a random effects model and heterogeneity (I2) was reported. Results: From 1,648 citations, 37 studies were included in this review. Heterogeneity was very high, precluding pooling. Only one of the included studies documented the use of CHADS2 scores by attending physicians; while no studies documented the use of HAS-BLED. There was variability in the ED management strategies of AFF. The utilization of rhythm control in the treatment of AFF ranged considerable (OR: 0.04-9.84) in comparison to rate control. Of the 17 studies reporting cardioversion approaches, chemical (9 {53%}) cardioversion was the most common management strategy of AFF. Conclusion: Our results suggests that either few physicians are documenting stroke risk scores in adult patients with AFF, or that research studies assessing ED management of AFF are not reporting scores documented by the attending physicians. Future research needs to examine the use of stroke risk scores to determine the optimal and appropriate care for patients.