137 patients suffering from classical or complicated migraine were investigated in the Neurology Department of the University of Vienna between 1971 and 1984. 13 of these patients were found to have pathological alterations and their case histories are presented. Clinically, 11 patients suffered from migraine accompagnée (in 2 cases accompanied by epileptic seizures), 1 patient had ophthalmoplegic migraine and 1 had a subarachnoid haemorrhage imitating migraine. The underlying pathological findings were: 1 tumour, 4 arteriovenous malformations, 4 aneurysms, 1 arterio-venous shunt, 1 pathological vascular network, 1 Moya-Moya syndrome and 1 intracerebral haemorrhage without detectable source of bleeding. 8 of the patients underwent successful surgery and most of them showed subsequent clinical improvement. The family history was positive in only 2 patients. The time interval between the occurrence of the first symptoms and the establishment of the final diagnosis was up to 25 years. The neurologist should undertake extensive investigation of the patient, including cerebral angiography, if the following criteria apply: hemicrania consistently on the same side; change in type of headache after a number of years; uniform complicating neurological symptoms; additional occurrence of epileptic seizures; manifestation of neurological symptoms after the prodromal phase; persistent neurological signs without remission; negative family history; persisting diffuse or locally accentuated EEG changes; pathological CAT results.