OBJECTIVES: While the cost of managing patients with myocardial infarction has been extensively studied, few data are available on the cost of managing unstable angina (UA) patients. The aim of the study was to assess the cost of UA patients in six European countries (France, Belgium, Italy, Spain, Sweden, UK). METHODS: A cohort simulation model was used. Patients entered the model when hospitalised for UA. Resources use during initial hospitalisation (length of stay, invasive procedures) was extracted from a prospective database. The frequency and type of following rehospitalisations for cardiovascular events were derived from a recent clinical trial. The time horizon was nine months and the perspective was that of the health care system. The hospital costs used for each country were based on the local DRG system. Official costs of outpatient medications were used. All costs are expressed for year 2001. RESULTS: The global cost of managing UA patients over a nine-month period was divided in three parts: cost of initial hospitalisation, cost of subsequent hospitalisations and cost of medications. Total length of stay of initial hospitalisation ranges from 7.2 days in Sweden to 10.8 days in Spain. The number of days in intensive care unit ranges from 1.6 in UK to 3.8 in Italy. In France, the global cost was estimated at €7471 per patient, breakdown of cost was as follows: initial hospitalisation (57%), subsequent hospitalisations (33%), medications (10%). For other countries, the global cost per patient was as follows: Belgium €6987, UK £3083, Italy €6908, Spain €6633, Sweden SEK 57608, with a consistent breakdown across countries. CONCLUSION: First hospitalisation is the main cost driver. Nevertheless the cost of subsequent hospitalisations accounts for about one third of the total cost highlighting the need for preventive treatment of subsequent cardiovascular events in UA patients.