For patients with chronic intractable headache, we compared a new treatment and a traditional one. Fifty-five patients (36 dependent on ergotamine, analgesics, diazepam, or corticosteroids) were given IV dihydroergotamine (DHE) and metoclopramide every 8 hours. Fifty-four age- and sex-matched patients (38 drug-dependent) were given diazepam intravenously every 8 hours. Forty-nine of the 55 DHE-treated patients became headache-free within 48 hours, and 39 of them sustained benefits in a mean follow-up of 16 months. In contrast, 7 diazepam-treated patients became free of headache within 3 to 6 days, and 31 had improved somewhat in 10 days. Repetitive IV DHE helps to terminate cycles of intractable migraine.