During a six month period, intramuscular dihydroergotamine mesylate (1 mg.) was given to 43 patients (75 headache episodes) who presented to the office after oral medications failed to abort their headaches. Headaches were successfully aborted in 71%, with most responses occurring between 30-minutes and 4-hours after injection. Side effects were common (61%) but not serious; sedation developed in 25%, nausea in 24%, transient worsening of headaches in 15%, body aches in 11%, diarrhea in 5%, and in 13%, headaches that were successfully aborted relapsed within 24 hours. Intramuscular dihydroergotamine, although under-used, is cost effective, practical, and well suited for busy medical offices. Its appropriate use can reduce the need for narcotic analgesics and emergency room visits.