OBJECTIVES:  In 2005 the Swedish pharmaceutical benefits board published a review concluding that rizatriptan 10 mg was one of the most cost-effective triptans for treating migraine, although efficacy differences among the triptan class were generally small. However, since the review, the price of sumatriptan has declined due to generic product entry. In this study, we sought to investigate the cost-effectiveness of rizatriptan versus generic sumatriptan. METHODS: A published Canadian decision-analytic model (Thompson et al., Pharmacoeconomics 2005) was adapted to estimate treatment costs and effects of rizatriptan 10 mg versus (generic) sumatriptan in a single migraine attack over a 24-hour time-frame in Sweden. Values modified from the published model were the substitution of Swedish healthcare and productivity costs, and updated data on 2-hour and 2-24 hour pain freedom (including results from more recent head-to-head trials of the comparators). As both sumatriptan 50 mg and 100 mg are marketed in Sweden, and have comparable efficacy profiles, averaged data for the two doses were used as a comparator to rizatriptan 10 mg. RESULTS: From a societal perspective, including both health care and productivity costs, the comparison of rizatriptan 10 mg versus (generic) sumatriptan resulted in cost-savings of ~ 5 SEK, and greater QALYs for rizatriptan 10 mg. Inclusion of health care costs only, yielded a cost-effectiveness ratio for rizatriptan vs. sumatriptan of 343,929 SEK/QALY.  CONCLUSIONS:  Given the data and assumptions used, in a single attack model, rizatriptan 10 mg was found to have a cost-effectiveness ratio compared to (generic) sumatriptan within the range typically regarded as cost-effective in Sweden. These findings suggest that there is reason to explore the cost-effectiveness of pharmaceutical and other medical interventions with large differences in acquisition cost even though efficacy differences may appear to be small.