OBJECTIVES: Rivaroxaban is a new oral anticoagulant subsidised on the Australian Pharmaceutical Benefits Scheme (PBS) for prevention of stroke or systemic embolism in patients with non-valvular atrial fibrillation or undergoing hip and knee replacement.  Recent randomized controlled trials (RCTs) have demonstrated its efficacy and safety in treating patients with acute coronary syndrome (ACS). The aim of this study was to assess the long-term cost-effectiveness of treating patients with ACS with rivaroxaban for a  12 month period and modelling the lifetime costs and benefits from a third party payer perspective.  METHODS: A two-part decision model was constructed to compare treatment with rivaroxaban or current treatment for patients with ACS. The first part was a decision-tree model comprising four health states (no event, non-fatal MI, non-fatal stroke, death) adopted to simulate treatment outcomes based on the event rates reported in the RCTs) health care costs (PBS, hospital cost weights) and quality of life weights  (from published literature) for 12 months. Beyond 1-year, treatment outcomes were estimated via a Markov model, with lifetime costs, and quality adjusted life years (QALYs) estimated for both arms and an Incremental cost-effectiveness ratio (ICER) estimated.  A series of sensitivity analyses were performed to test the robustness of the result.  RESULTS: One-year treatment with rivaroxaban was associated with both incremental cost and QALY (AUD 30688 vs. 30101, 17.51 vs. 17.39 for rivaroxban and placebo respectively) over lifetime horizon in the baseline analysis. The ICER of rivaroxaban comparing to placebo was AUD 4896 per QALY gained. The probabilistic sensitivity analysis varying the event transition probability also showed consistent results.  CONCLUSIONS: Based on clinical and health economic evidence, treating ACS patients with rivaroxaban for 12 months was associated with an ICER of AUD 4896/QALY, which is below the Willingness-to-pay per QALY threshold in Australia inferred from published literature.