OBJECTIVE: In Canada, the clinical use of triptans is restricted by many health plans, despite their proven superior efficacy in the treatment of moderate to severe migraine. This analysis estimates the clinical consequences, costs and cost-effectiveness of Rizatriptan compared to other triptans and UC in Ontario, Canada. METHODS: A decision analytic model was created to estimate migraine treatment costs and clinical outcomes observed over a 24-hour period from therapy initiation, in patients with a diagnosis of moderate to severe migraine as defined by International Headache Society (IHS) criteria. Efficacy measures consisted of pain-free patients at 2 and 4 hours and those sustained pain-free for the following 2 to 24 hours. Rizatriptan was compared to other triptans based on data from a meta-analysis, and compared to UC based on other published data. Costs of therapies were used to determine incremental costs per attack aborted as well as cost per QALY. Both a Ministry of Health perspective (direct costs) and a societal perspective (direct and indirect costs i.e. time loss from paid and unpaid work) were included. One-way sensitivity analyses were conducted to validate the robustness of the model. RESULTS: Cost estimates are similar to the previously published Canadian studies. Rizatriptan compared to UC produced a cost per QALY gained of $31,845. When the societal perspective was considered the cost per QALY decreased to $5263. Rizatriptan had a substantial advantage over UC in pain-free results at 2 and 4 hours, resulting in a modest incremental costs of $49.82 and $58.48 per attack aborted respectively. In addition, Rizatriptan dominated all other triptans on all measures considered; it was both more effective and less costly. CONCLUSION: This study shows that treatment with Rizatriptan for patients who suffer from moderate to severe migraines constitutes a cost-effective strategy for improving care of migraine patients in Canada.