The definition of familial hemiplegic migraine is still unsettled. We report the case of a young man who has had hemiplegic migraine attacks for ten years. CT of the brain was abnormal with a low density in the temporal lobe, suggesting infarction and probably having no relation to the attacks. There was a clear family history of hemiplegic migraine, possibly with the same type of attack. Ergotamine tartrate seemed to be effective in preventing headache. This case challenges the current clinical definition of familial hemiplegic migraine, in that while the attack pattern was hereditary, the hemiplegia occurred as an aura rather than accompanying and outlasting the headache.