OBJECTIVES: To compare costs and effectiveness of dabigatran etexilate (DAB) versus acetylsalicilic acid (ASA) in patients with Non-Valvular Atrial Fibrillation (NVAF) from a private and public health care system perspective in Brazil. METHODS: A Markov model was built to compare DAB versus ASA to derive incremental cost effectiveness ratio (ICER) of DAB based on  a mixed treatment comparison and a modified Delphi panel with Brazilian experts (local clinical practice pattern on the management of NVAF patients). The model estimated the number of ischaemic and haemorrhagic strokes, systemic embolisms, intracranial hemorrhages, transient ischaemic attacks, extracranial hemorrhages, minor bleeds and acute myocardial infarctions associated with the respective treatments. To each clinical event costs, disabilities and/or reduction in quality of life, and risk of death were assigned. Only direct medical costs were considered and a discount rate of 5% was assumed, according to Brazilian HTA guidelines. A probabilistic sensitivity analysis was designed to assess uncertainty. RESULTS: Under both, the private and public perspective, DAB was associated with additional 0.31 life years gained (LY), additional 0.60 QALYs and demonstrated a lower incidence of intracranial events versus ASP, resulting in a lower event costs (-R$ 1,057.84 and - R$ 3,006.07) and follow up costs. The ICER for DAB versus ASA was R$ 38,511.06/LY and R$ 31,379.80/QALY from the public perspective and DAB was dominant from the private perspective. Sensitivity analyses confirmed the cost-effectiveness of DAB. CONCLUSIONS: Findings suggest that DAB can be cost-effective for stroke prevention when used instead of ASA in NVAF patients in Brazil, given that DAB was dominant in the private sector and ICERS were below the threshold of other technologies reimbursed in the public health care sector.