Migraine afflicts greater than 28 million adults in the United States. Acute treatments, such as almotriptan malate, target the symptoms of a migraine attack. Preventive treatments, such as topiramate, primarily target the generation of attacks and may decrease use of acute treatments. Preventive treatments, by a process of neurostabilization, may result in an additive effect on almotriptan malate to improve acute treatment intervention response during a migraine attack. This is a randomized, double blind, parallel group multicenter study that will enroll patients 18-65 years old with a history of 3-12 migraine headaches each month for the past 3 months. The total study duration will be approximately 32 weeks. The study is divided into 4 phases as follows: A Screening Phase that lasts one month; An Open Label Phase where all patients will be treated with topiramate gradually dosed to 100mg a day lasting 6 weeks; A Double Blind Phase lasting 19 weeks at which time patients will be randomized to stay on topiramate 100mg per day or switch to placebo topiramate (50:50 chance) and a Taper/Exit Phase lasting 2 weeks. Almotriptan malate will be used for all migraine headaches during the study as needed. The study hypothesis is that the combination of almotriptan malate and topiramate will have a better clinical response than the combination of almotriptan malate and placebo topiramate. Migraine pain information will be collected from each patient with the use of a Personal Digital Assistant (PDA or Palm Pilot) throughout the study for each migraine attack. Commercial Topiramate will be gradually increased to 100mg/day in approximately 4-6 weeks. You will then be randomized to either Topiramate or Placebo, dosed at 100mg a day, for the remainder of the study (18 weeks). AXERT 12.5mg may be taken to treat migraine headaches during the study.