Emergence delirium (ED), also referred to in the literature as emergence agitation (EA) or post-anesthetic excitement, is a well-documented phenomenon occurring in children and adults in the immediate postoperative period and lasting 5-15 minutes. Emergence delirium is a clinical condition in which patients are “awake” but experience alterations in disorientation and other mental status changes that range from confusion and lethargy to violent and harmful behavior. First addressed on a large scale in the 1960s, ED continues to gain recognition among anesthesiologists who have begun to document the potential pharmacological association and other pre-morbid predictors that increase the risk of developing ED. Investigators have attempted to define ED, validate appropriate assessment tools, distinguish potential risk factors, and identify acute management. The current paper reviews ED and explores theoretical subtypes of ED with and without pain/agitation for clinical assessment.