OBJECTIVES: The purpose of this study is (1) To build a pharmacoeconomic model to appropriately represent the outcomes of a single dose almotriptan treatment in migraine patients, and (2) To assess the cost-benefit of almotriptan compared to placebo based on clinical trial results. METHODS: Cost-benefit analyses from a societal perspective are performed. Time horizon of the model is defined as a single migraine episode, lasting one workday. The probabilities of individual events are based on clinical trial data published by Pascual et al (2000). Healthcare consumption probabilities, the likelihood of a physician or ER (emergency room) visits were drawn from Adelman et al (1996). Health care cost data are drawn from Hu et al (1999), who studied specifically the migraineurs' health care costs. Almotriptan cost is assumed to be equal to that of sumatriptan because almotriptan was not yet marketed in the USA at the time the analysis was performed. In order to evaluate the benefit from treatment, productivity gain/loss was converted to monetary terms using the average market wage in the United States. Average wage data are drawn from the Statistical Abstract of the United States, 1999. All health utilization costs and average daily wage were converted to year 2000 dollars using consumer price index (3%). The outcome measure for the cost-benefit model is net-benefit. RESULTS: Based on the model used in this study, almotriptan is more cost-beneficial than placebo, the difference of net-benefit being $10.62. Breakeven point is reached at the price of $26.62 for almotriptan. Placebo will become more beneficial than almotriptan when almotriptan cost $26.52 and above. CONCLUSIONS: Even though a relatively large placebo effect is observed in migraine treatment, when almotriptan price is $26.62 and below, almotriptan is the preferred choice of treatment to society over placebo treatment considering net-benefit.