Headache is the fifth most common primary complaint of patients presenting to an emergency department (ED) in the United States. The emergency physician (EP) plays a unique role in the management of these patients, one that differs from that of the primary care physician, the neurologist, and other specialists. Diagnostic nomenclature used in the ED is necessarily less specific, as care is more appropriately focused on the relief of symptoms and the identification of life-threatening causes. By seeking a limited number of specific critical features on history and physical examination, the EP can minimize the risk of overlooking one of these dangerous causes of headache. When certain features are present, empirical therapies and diagnostic testing should be initiated in the ED. The most frequently encountered pitfalls in the management of patients with headache in emergency medicine practice, and those with the greatest likelihood to adversely affect patient outcomes, are discussed.