The effectiveness of dihydroergotamine administered by home subcutaneous injection by the patient or family for severe headache attacks was assessed retrospectively in 51 patients. Average follow-up was 21 weeks. Twenty-one patients had intermittent migraine attacks, 27 had transformed migraine with chronic daily headache, and 3 had chronic tension-type headache. Of the 51 patients taught home injection, 35% had an excellent overall response, 18% had a good response, 12% had a poor response but continued to use dihydroergotamine, and 35% had discontinued dihydroergotamine use. Side effects were the main reason for stopping dihydroergotamine. These included nausea or vomiting or both, limb pain or numbness or both, chest or throat tightness or both, and soreness at the injection site. Thirty-three patients (65%) continued to use dihydroergotamine at the end of the follow-up period. In patients who previously required injections from medical personnel for headache crises and in whom home injection of dihydroergotamine was effective, a dramatic reduction occurred in hospital emergency room and physician office utilization. Dihydroergotamine use by home injection can be an effective treatment for a significant proportion of patients with severe migraine including patients with transformed migraine and medication overuse.