Pediatric emergency medicine is a field beset with ambiguity. First there is the name. The field includes more than just emergencies, yet less than all of outpatient pediatrics. Perhaps the name should be pediatric emergency department medicine, for the common factor among the patients is that they come to the emergency room (ER). Some patients have problems for which ER management is the solution. For others the ER is but a conduit to the hospital bed, where perhaps a prolonged diagnostic or therapeutic stay ensues. And for others with a chronic illness, an acute exacerbation or an associated or unassociated problem brings the patient to the ER for episodic therapy. This array defines a second problem: What is the breadth and depth of the field? How much detail of which diseases constitutes adequate and appropriate coverage of the subject matter? Where does ER treatment end and inpatient treatment begin?