OBJECTIVES: The use of early coronary catheterization and revascularization in unstable coronary artery disease (UCAD) varies, which could have important consequences for patients as well as long-term costs. The objective of this study was to estimate the long-term cost-effectiveness and cost-utility ratios of this strategy. METHODS: We analysed data in the open randomized, clinical FRISC II invasive trial, which consisted of total 2457 patients, with signs and symptoms of UCAD. We prospectively recorded the patients' use of health services as well as productivity losses. Health states scores were obtained within the trial five times during the 2-years follow-up. Results were analysed in both a societal and a health care provider perspective. The uncertainty was handled using the net-benefit approach. RESULTS: There was a significant 1.74 % absolute reduction in mortality in the invasive compared to the non-invasive group at two-years follow-up. The difference in mean total cost was SEK 11,386 $1,467). This difference was not significant. The estimated cost per quality adjusted life year (QALY) gained for the invasive strategy, based on within trial results and projected life expectancy, was SEK 22,873 ($2,948). The estimated cost per life year gained was SEK 57,651 ($7,429). If costs of added life years were included the cost per quality adjusted life year was SEK 78,077 ($10,061). CONCLUSIONS: Invasive strategy in patients with unstable angina or non-ST-segment elevation myocardial infarction, was in the long-term perspective shown to be cost-effective. The results were consistent in all subgroups.