Syncope is a common presenting complaint to the emergency department (ED). Its assessment is difficult. Some serious causes of syncope are transient and patients with a potentially life threatening condition may appear well by the time they reach the ED. Accurate history taking is vital and is often diagnostic whilst identification of a cardiac cause is associated with an increased mortality. This is related to underlying cardiac disease; patients presenting with syncope who have significant cardiac disease should be investigated thoroughly to determine the nature of the underlying heart disease and the cause of syncope. Early work suggested that as many as 30% of patients with cardiac syncope died within one year of presentation. This led to physicians admitting many patients with unexplained syncope however presently there is little evidence that focussed investigation, or even admission leads to an improved prognosis. Studies looking at syncope clinical decision units have though shown these to be of some benefit. Risk stratification studies on syncope in the ED have attempted to help emergency physicians target high-risk patients once those with clearly identifiable conditions have been identified and managed. These clinical decision rules have suffered from poor external validation and in the USA where many of these tools were developed, a universal consensus approach remains lacking. Although no individual tool has yet been successfully implemented into standard practice, as a whole they have probably enabled emergency physicians to become more aware of the risk factors that are likely to lead to poor outcome. It is likely that serious outcome in syncope although significant, is not quite as common as previously thought. Presently the American College of Emergency Physician (ACEP) guidelines are the most useful guidelines written for the emergency physician. With biochemical markers showing some promise, further work may lead to incorporation of these into existing clinical decision rules and guidelines to improve their sensitivity and specificity.