OBJECTIVES: Aortic stenosis is the most common valvular heart disease in the elderly –its prevalence is estimated to be up to 5% in individuals over 75 years. Surgical replacement of aortic valve is considered the standard care and in the absence of serious coexisting conditions, the procedure is associated with low operative mortality. However, a significant proportion of patients cannot undergo surgery due to high surgical risk associated with advanced age or presence of multiple coexisting conditions. Treatment with transcatheter aortic-valve implantation (TAVI) is a therapy with potentially lower peri-procedure risk and has been used as a therapeutic option in this group considered inoperable. This study aims to develop a cost-effectiveness analysis of TAVI in patients with severe aortic stenosis who are not suitable for surgical treatment according to Brazilian Private System Perspective. METHODS: A Markov model was developed to compare TAVI versus standard therapy (drug treatment with or without aortic balloon valvuloplasty) with a 5-year time horizon. Outcomes in the model were based on safety and effectiveness (as measured by clinical outcomes of chance of successful implantation procedure and survival from PARTNER cohort B trial). Resource use included early perioperative complications (30 days) and late events. Cost data were obtained from Brazilian public lists (CMED/SIMPRO/CBHPM).  Results were expressed as incremental cost-effectiveness ratio (ICER) per life years gained (LYG). Probabilistic sensitivity analysis was performed to confirm robustness of results. RESULTS: Compared with standard therapy with or without aortic balloon valvuloplasty, use of TAVI improves survival in 0.97 life years with an incremental cost of US$43,602, resulting an ICER of US$45,080/LYG. In an alternative scenario considering 10-year time horizon, ICER was 27,565/LYG. CONCLUSIONS: Use of TAVI results in improved survival with a low risk of serious adverse events, and demonstrates a cost-effectiveness profile when compared to other technologies already incorporated in Brazil.