OBJECTIVE To compare the efficacy and tolerability of sumatriptan nasal spray (NS; 5 mg, 10 mg, and 20 mg) with placebo for the treatment of acute migraine in adolescents. METHODS A randomized, double-blind, placebo-controlled, single-attack study was conducted in 653 US adolescents (12-17 years of age). Patients with at least a 6-month history of migraine, who met International Headache Society criteria for migraine (with or without aura) were eligible for participation. Headache relief 2 hours postdose, complete relief, presence or absence of associated symptoms, headache recurrence, and use of rescue medications were recorded. The primary efficacy endpoint was headache relief 2 hours postdose sumatriptan NS (20 mg) versus placebo. Safety and tolerability were assessed by examining adverse events, changes in electrocardiograms, vital signs, physical examinations, and clinical laboratory tests. RESULTS Headache relief 1 hour postdose was significantly greater for patients using 10 mg (56%) and 20 mg (56%) of sumatriptan NS compared with placebo (41%). Headache relief 2 hours postdose was significantly greater for patients using 5 mg of sumatriptan NS (66%) compared with placebo (53%), and approached statistical significance for 20 mg (63%) compared with placebo (53%). Complete relief 2 hours postdose was significantly greater for patients using 20 mg of sumatriptan NS compared with placebo (36% vs 25%, respectively). Each dose of sumatriptan (5 mg, 10 mg, and 20 mg) was superior to placebo with respect to the cumulative percentages of patients first reporting headache relief within 2 hours of dosing (Kaplan-Meier). The sumatriptan 20-mg dose was superior to placebo with respect to the cumulative percentages of patients first reporting complete relief within 2 hours of dosing (Kaplan-Meier). Photophobia and phonophobia were significantly reduced 2 hours postdose for sumatriptan NS (20 mg), compared with placebo (36% vs 48% and 25% vs 44%, respectively). Taste disturbance was the most commonly reported adverse event (2%, 19%, 30%, and 26% for placebo, 5 mg, 10 mg, and 20 mg, respectively). No drug-related serious adverse events or clinically relevant changes in laboratory parameters, electrocardiograms, or vital signs were reported. CONCLUSIONS Sumatriptan NS is effective and well-tolerated for the treatment of acute migraine in adolescents, with the 20-mg dose providing the best overall efficacy and tolerability profiles.