OBJECTIVE: To examine the cost-effectiveness (CE) of atorvastatin compared to simvastatin in the treatment of patients with dyslipidemia in the Netherlands. METHODS: The cost-effectiveness was evaluated using effectiveness data from the LIZO trial, a 3-month clinical trial in which patients were compared on milligram-equivalent doses of either 20 or 40 mg atorvastatin or simvastatin. Short-term (three month) cost-effectiveness was assessed based on the percentage of patients reaching EAS or NCEP ATP-II LDL treatment targets, and drug cost. These results were extrapolated to a 10-year period. This long-term CE-evaluation assessed drug costs, CHD-event costs, and life years gained. Patients reaching target cholesterol levels and remaining on drug treatment were assumed to have a maximum reduction in risk of CHD events during the 10-year period; patients not reaching target levels were assumed to have an average risk reduction for CHD-events. Risk calculation for CHD-events was based on Dutch CBO-guidelines. Cardiac events were assumed to occur after 5 years. One- and two-way sensitivity analyses were performed. RESULTS: Short-term cost-effectiveness analyses showed cost-effectiveness between €51 and €422 per successfully treated patient. The results of the long-term analyses indicated dominance of the atorvastatin treatment in the 20 mg group using both EAS and NCEP-guidelines. For patients treated with 40 mg, dominance was observed using NCEP-guidelines and cost-effectiveness of €7,889 per life-year gained using the EAS-guidelines. In the sensitivity analyses the results were robust and below the €18,000 benchmark stated in the Dutch guidelines, with the exception of time of occurrence of CHD events. CONCLUSION: This CE-analysis regarding dyslipidemia treatment is the first evaluation conducted in the last 10 years in the Netherlands. The study showed low cost-effectiveness for the short-term evaluation and cost-savings for atorvastatin in comparison to simvastatin in 3 of the 4 evaluations in the long-term CE-analyses.