OBJECTIVES: Clopidogrel (in addition to aspirin) for the treatment of all patients with acute coronary syndromes (ACS) was recently approved for additional reimbursement under the Australian Pharmaceutical Benefits Scheme. We sought to estimate the implications of this approval for the Australian healthcare system. METHODS: A Markov model to determine cost-effectiveness was constructed by extrapolation of data from the Australian Acute Coronary Syndromes Prospective Audit (ACACIA) registry (n=2553) in the first model cycle, and the Reduction in Atherothrombosis for Continued Health (REACH) registry (n=2567) in subsequent model cycles. Efficacy data were drawn from the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial. Drug, cardiovascular disease and hospitalisation costs were sourced from the literature and health care reimbursement fees. These were updated as required using Australian health price indices. An annual discount rate of 5% was applied to all costs and effects beyond one year in accordance with reimbursement guidelines. Data regarding the prevalence of ACS was estimated from published national Australian epidemiological and demographic data. As clopidogrel is already reimbursed for patients who have taken aspirin prior to their event, or who cannot take aspirin due to allergy or intolerance, literature was reviewed to estimate this population. RESULTS: The estimated number of newly eligible patients ranged annually from 48,100 to 62,700 over five years. The expanded treatment coverage was estimated to prevent an additional 12,400 major cardiovascular events (comprising myocardial infarctions, strokes and deaths) in the first five years, leading to a saving of A$175 million in health care costs arising from avoided hospitalisation, procedures and medications. This has major resource implications for the Australian health system in terms of staffing, bed availability and emergency admissions. CONCLUSIONS: The imminent implementation of unrestricted access to clopidogrel plus aspirin for all ACS patients is likely to lead to significant health and cost-savings for Australia.