Almotriptan malate (AXERT®) is approved for the treatment of migraine headache, with or without aura, in adults. This is a multicenter, randomized, double-blind, placebo-controlled, parallel group study of adult patients with a diagnosis of migraine headache, with or without aura. Patients will be randomized (like with the toss of a coin) to receive almotriptan malate (AXERT®) or placebo for the treatment of 3 consecutive qualifying migraine headaches. After screening, patients will leave the study center with blinded study medication and an electronic subject diary (Personal Digital Assistant [PDA]). Patients will self-dose with study medication as soon as headache pain of any intensity begins (that resembles their usual migraine), but no later than 1 hour after headache pain begins. Patients will use their PDAs to record assessments such as pain intensity, symptom severity and ability to function as related to the headaches. The primary hypothesis of this study is that the percentage of patients who are pain free two hours after taking study drug at the earliest onset of headache pain is greater in the almotriptan malate (AXERT®) 12.5mg group than in the placebo group and almotriptan malate (AXERT®) is generally well-tolerated.