Twelve children with migraine symptoms that did not respond to conventional analgesics completed a double-blind, placebo-controlled, cross-over study of two doses of oral dihydroergotamine (DHE) for acute treatment. The primary endpoint was reduction of headache by > or = 2 grades on a 5-grade scale at 2 hours. After DHE, 7 of the 12 children reached the primary endpoint, and 2 reached the primary endpoint after placebo [difference 42%; 95% confidence interval (CI) 14%-70%]. Five of the 7 were pain-free after DHE (3 with 20 micrograms/kg; 2 with 40 micrograms/kg); none was pain-free after placebo. Headache recurred in 2 of the 5. Although headache recurrence limits the efficacy of oral DHE, it may be useful in the acute treatment of migraine in selected children.