OBJECTIVES: PROVE-it is the first trial comparing an intensive lipid-lowering treatment with 80mg Atorvastatin vs 40mg Pravastatin in acute coronary syndromes (ACS) with a 2-year follow-up. There were significantly less morbimortality with 80mg atorvastatin vs 40mg pravastatin: 22.4% vs 26.3% (p=0.005). The objective of this economic evaluation is to estimate the incremental cost-effectiveness of atorvastatin vs pravastatin with Spanish costs based on PROVE-IT. METHODS: Cost-effectiveness analysis was performed under the perspective of the Spanish health system, projected in the long-term by modelizing with a decision tree, estimating average life expectancy by the Framingham cohort. Only drug acquisition costs and direct cots were considered. Costs were expressed in 2005€. Effectiveness was measured as primary events avoided (all cause mortality, AMI, unstable angina, revascularization and stroke) and life years gained (LYG). Mean cost per patient and incremental cost effectiveness ratio were calculated as cost per event avoided and cost per LYG. An univariate sensitivity analysis was performed for different acute events costs. RESULTS: Mean cost expected per patient during the 2 years of follow-up was 3,180€ for atorvastatin and 3,210€ for pravastatin. Incremental saving of atorvastatin vs pravastatin was 30€ per patient, because the saving for events avoided by atorvastatin overweights its higher acquisition cost. Benefit of atorvastatin vs pravastatin was 0.103 life years per patient. Incremental cost-effectiveness of atorvastatin vs pravastatin was 543€ per event avoided and 296€ per LYG. These results were robust to the sensitivity analysis. CONCLUSIONS: Under the perspective of the Spanish health system, intensive treatment with 80mg atorvastatin is a more effective treatment and is less costly than 40mg pravastatin, in acute coronary syndromes, according to a model based in the PROVE-it trial. Therefore treatment with atorvastatin 80mg is a dominant or cost-saving strategy, allowing other Spanish resources to be used on other treatments.