Inclusion Criteria:

• Patient weighs at least 20 kg (44 pounds)
• Patient has had a history of migraine with or without aura > 6 months with >= 1 to <= 8 moderate or severe migraine attacks per month in the 2 months prior to screening Visit 1
• Patient has a history of migraine defined by International Headache Society [IHS] migraine definitions
• Patient is willing to stay awake for at least 2 hours after administration of the first dose of study medication
• Patient has not experienced satisfactory relief from migraine pain with nonsteroidal anti-inflammatory drugs (NSAIDs) or N-acetyl-p-aminophenol (APAP) treatment
• The parent or guardian and patient agree to the patient's participation in the study as indicated by parental/guardian signature on the consent form and patient assent
• For patients taking migraine prophylactic medication, treatment regimen is stable and has been taken for at least 3 months prior to Visit 1.

Exclusion Criteria:

• Patient is pregnant or breast-feeding, or is a female expecting to conceive within the projected duration of study participation
• Patient has a history of mild migraine attacks or migraines that resolve in less than 2 hours
• Patient has basilar or hemiplegic migraine headaches
• Patient has >15 headache-days per month OR has taken medication for acute headache on more than 10 days per month in any of the 3 months prior to screening
• Patient has uncontrolled high blood pressure, uncontrolled diabetes, HIV, any cancer, or any other significant disease
• Patient has a history or clinical evidence of cardiovascular problems or stroke
• Patient has either demonstrated hypersensitivity to or experienced a serious adverse event in response to rizatriptan
• Patient did not experience satisfactory relief from migraine pain to prior treatment with 2 or more adequate courses of 5HT1 agonists
• Patient has a recent history (within the past year) or current evidence of drug or alcohol abuse or is a "recreational user" of illicit drugs
• Patient is currently taking monoamine oxidase inhibitors, methysergide, or propranolol, and is unable to tolerate withdrawal of these medications for the intervals required
• Patient is currently participating or has participated in a study with an investigational compound or device within 30 days of screening
• Patient is legally or mentally incapacitated.