The frequency and clinical characteristics of headache were assessed in a prospective study carried out among 100 patients suffering from ischaemic infarct in the area of the middle cerebral artery. Headache was found in 28 out of the 100 patients studied and proved to be significantly more frequent in those infarcts located in the superficial branches (p < 0.001) and in the dominant hemisphere (p < 0.05). We found no relationship between the existence of headache and the type of infarct, its extension or level of neurological affectation. Severe headache preceded stroke in 28.5% of cases, was simultaneous in 57.1% and followed in 14.2%. The average intensity of headache was 2.14 +/- 1.69 headache units. It was bilateral in 46.4% of patients, generalized in 14.2%, unilateral on the side of the infarct in 28.5% and counterlateral in the remaining 10.7%.