Three cases of intracranial arteriopathy associated with the administration of ergot derivatives are reported. In the first case, excessive doses of dihydroergotamine and of ergotamine tartrate seemed to be the cause, but simultaneous treatment with an antibiotic and the existence of a cytomegalovirus infection could have favoured the arteriopathic process. The second patient also received excessive doses of these two drugs, but in addition she was taking oestrogen and progesteron containing contraceptives. In the third case, an intravenous injection of methylergometrine in a dose of 0.2 mg seemed to have initiated the arteriopathy. Arteriograms were comparable in all three cases, with segmental stenosis of several cerebral arteries, whereas internal carotid and vertebral arteries remained normal. In the first case a control cerebral arteriography was normal one month later. These findings suggest that widespread cerebral arteriopathy can appear in subjects who chronically abuse ergotamine tartrate.