In emergency medicine, the need to make rapid decisions with sometimes limited data sets the decision-making apart from other medical specialties, showcasing unique features of decisiveness despite uncertainty. The primary and immediate goal is not necessarily diagnosis or long-term planning but the rapid stabilization of a patient’s condition and determination of the most suitable disposition. Disposition is a complex and critical problem that directly impacts patient outcomes. It presents clinicians with a wide variety of options including outpatient management if the patient’s condition is stable, on-site observation, admission to a wide selection of inpatient services, or patient transfer to a healthcare facility with better expertise and resources to manage the patient. To prevent errors that may lead to delays and harm, emergency medicine decision-making relies on a deliberate and selective collection of relevant signs, symptoms, and diagnostic data driven by the chief complaint.