This article covers the general approach to patients who present to the emergency department with a complaint of dizziness or vertigo, and altered mentation. Patients’ histories and physical examination findings are discussed first, then a pertinent differential diagnosis, ranging from neurological causes and poor perfusion states to toxicologic causes, is described along with the distinguishing features and potential diagnostic pitfalls of each problem. Case scenarios are presented and the treatment and disposition of patients from the emergency department are discussed.