To evaluate the clinical features of headache in stroke, a prospective study was carried out in 240 consecutive patients with acute stroke who had intact expressive function. Headache occurred in 38%: 32% of 195 patients with ischemic stroke and 64.5% of 45 patients with hemorrhagic stroke (p < 0.0001). Headache patients were younger (mean age 62 ± 15 vs 67 ± 11.5 years) than non-headache patients (p < 0.01). A history of previous vascular or tension-type headache was found in 40.5% of the headache group, but in only 23.5% of the non-headache group (p < 0.01). In ischemic stroke, headache was observed in 41% of thrombotic infarcts, in 39% of cardioembolic infarcts, in 23% of lacunar infarcts and in 26% of TIA. Headache was significantly more common in thrombotic than lacunar infarcts (p < 0.05). In hemorrhagic stroke, headache was observed in all subarachnoid hemorrhages and in 58% of intraparenchymal hemorrhages. In ischemic stroke, the mean duration of the headache was 25 ± 28 h and in hemorrhagic stroke 64.5 ± 36.5 h (p < 0.00001). In ischemic stroke the headache was focal in 74% and mild or moderate in intensity in 74%. In hemorrhagic stroke, it was diffuse in 52% and the pain intensity was incapacitating in 70%. Headache was more common in vertebrobasilar stroke (59%), in comparison with carotid stroke (26%) or stroke of unclear vascular topography (33%) (p < 0.00001). Fifty-six and a half percent of patients with cortical stroke had headaches, as opposed to only 26.5% of patients with subcortical stroke (p < 0.005). Ten percent of the patients presented with sentinel headache.