OBJECTIVES: To compare cost-effectiveness (CE) of rosuvastatin (RSV) and ezetimibe/simvastatin (E/S) in patients with treated dyslipidemia to assess achievement of treatment goals established by Adult Treatment Panel III (ATPIII). METHODS: Clinical data was obtained from the files of dyslipidemic patients that attended from January 2004 to December 2005 to a Cardiology Hospital in Mexico City. Patients treated with either RSV 10mg/day or E/S 10/20mg/day and with lipid determinations before (basal) and after 8 weeks of treatment were included. The perspective of the analysis was from the point of view of the provider, and the cost of the drugs that was obtained by a local wholesaler (NADRO, Oct 2006). Effectiveness was measured with subrogates end points, achieving ATPIII lipid goals and lowering LDL-C levels. The precision of the CE estimate was assessed by the bootstrap method, using 1000 re-samplings and by net monetary benefit approach. Horizon time was 8 weeks. Acceptability curves were built to assess uncertainty. Sensitivity analysis included threshold, one-way and scenario assessment. RESULTS: Ninety-eight patients received RSV (age 63.1±12.4 years) and 89 patients received E/S (age 65.8±12.8 years). In the RSV group 81.4% and 46.4% patients achieved 2001 and 2004 lipid goals respectively, versus 58.4% and 31.5% E/S patients (p<0.01). LDL-C mean percentage reduction was: RSV -46.7±13.6 versus E/S –35±21.3 (p<0.001). Average per patient costs in USD were 94.35 for RSV (85.4 - 109.8) and 143.01 for E/S (127.42 – 161.64). RSV showed to be less costly and more effective than E/S for achieving ATPIII goals and reducing LDL-C levels. Acceptability showed that independently of willingness to pay, RSV is CE in 97% of scenarios compared to E/S. Sensitivity analysis showed the robustness of results. CONCLUSION: On clinical practice RSV is more CE in attainment of ATPIII goals and lowering LDL-C levels in Mexican patients.