OBJECTIVE: Results from the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) study showed that clopidogrel plus aspirin, comparing to aspirin alone, reduced the cardiovascular events (death, myocardial infarction, and stroke) in patients with acute coronary syndromes (ACS). Yet the acquisition cost of clopidogrel is much higher. It would therefore be worthwhile to compare the long term cost impact of these 2 regimens. METHODS: Until recently, only very few patients with ACS received a clopidogrel-aspirin combination therapy in Hong Kong. Therefore a hypothetical cohort was formed and compared to a real group of patients treated with aspirin alone. For the aspirin group, medical history was reviewed and cardiovascular and gastrointestinal events occurring in a period of 12 months after initiation of therapy were recorded. The target cost items included hospitalisation, emergency room visits, outpatient clinic visits, related medications, diagnostic tests, procedures and surgery. For the hypothetical cohort, the probabilities/relative risks for clinical events were adopted from the CURE study. The unit cost of drugs and other resource items were based on the Hong Kong Hospital Authority drug acquisition cost 2001 and Hong Kong Government Gazette 2003 respectively. The perspective of the study was that of a public health organisation. RESULTS: Fifty-four consecutive patients with ACS receiving aspirin therapy were identified over the period of January 1, 2001 to December 31, 2001 from a major public hospital in Hong Kong and studied. The average cost of management per patient over the 10-month period of this group was HKD85,324 (USD$10,940, HKD7.8 = USD$1). Hospitalisation represented the major cost item (64.6%), followed by cost of investigational tests (14.5%) and procedural cost (11.6%). The average cost per patient in the hypothetical cohort was HKD83,903 (USD$10,757). CONCLUSION: According to our analytical model, the overall cost impact between clopidogrel plus aspirin vs aspirin alone in the 2 groups of patients was similar.