Objective.-To provide to emergency department (ED) physicians with guidelines for diagnosis of patients with nontraumatic headaches. Background.-Many patients present to an ED with the chief complaint of headache. Causes of nontraumatic headache include life-threatening illnesses, and distinguishing patients with such ominous headaches from those with a primary headache disorder can be challenging for the ED physician. Conclusion.-We present a consensus statement aimed to be a useful tool for ED doctors in making evidence-based diagnostic decisions in the management of adult patients with nontraumatic headache. Methods.-A multidisciplinary work performed an extensive review of the medical literature and applied the information obtained to commonly encountered scenarios in the ED.