The relationship between the cerebrovascular system and headache is multifaceted and incompletely understood. However, several important observations have been made. Head pain can be generated by stimulation of the intracranial vasculature. This is evident on an experimental level as well as with common vascular conditions. Headaches occur in association with ischemic strokes, cervical artery dissections, intracranial aneurysms, and following cervical or cranial vascular procedures. In addition, migraine has been identified as a risk factor for the development of vascular diseases such as ischemic stroke and cervical artery dissection. Patent foramen ovale, a structural cardiovascular disorder, is more common in patients with migraine with aura. In addition, certain rare migraine syndromes (aura without headache, hemiplegic migraine, retinal migraine, ophthalmoplegic migraine, and basilar-type migraine) may mimic stroke. Study of each of these entities will lead to a better understanding of the pathophysiology of headache and its relationship to the vascular system.