OBJECTIVES: Rosuvastatin (Crestor(r)) is a new statin with proven efficacy for reducing plasma low-density lipoprotein cholesterol (LDL-C) levels. A model has been developed to estimate the budget impact and incremental cost-effectiveness of rosuvastatin compared with other statins for reducing LDL-C levels and treating patients to goal. METHODS: The model considered the treatment of an adult population with hypercholesterolaemia over a 1-year period from the perspective of the UK primary Health care provider. The clinical benefit was a simulated estimate of the proportion of the population attaining the European Atherosclerosis Society (EAS) guideline goal LDL-C plasma level (<3 mmol/L). The model compared the cost of statin treatment using current prescribing patterns with a scenario in which 30% of patients currently receiving statins are switched to rosuvastatin. Patients are switched from existing products according to market share. Sensitivity analyses varied the potential prescribing share of rosuvastatin. RESULTS: Following rosuvastatin introduction, the anticipated cost saving for a population of 1,000 patients would be £8,052 (€12,849) per year, with an additional 103 patients reaching the EAS goal LDL-C level. Assuming a fixed budget, the introduction of rosuvastatin would allow an additional 30 patients to be treated with rosuvastatin, with a total 132 extra patients achieving the goal. The analysis showed that rosuvastatin is cost-effective compared with atorvastatin, pravastatin and simvastatin. Sensitivity analyses showed that the results were robust to changes in the prescribing share of rosuvastatin. CONCLUSION: The introduction of rosuvastatin into primary care prescribing should enable more patients to be treated with a statin than is currently possible, and more patients would reach EAS goal LDL-C levels. Compared with other currently available statins, prescribing rosuvastatin would allow resources to be used more efficiently. The model can be adapted for any European country to determine the cost-effectiveness and potential budget impact of a new statin.