OBJECTIVES: To evaluate the Budget Impact from the perspective of the Brazilian Private Health Care System after the introduction of abiraterone acetate (AA) for the treatment of metastatic castration-resistant prostate cancer (mCRPC) patients previously treated with docetaxel.  METHODS: An epidemiological model based on reports of Brazilian National Cancer Institute and published literature was developed to estimate the incidence of mCRPC patients in the next three years. Budget impact was simulated comparing current scenario, where all patients undergo treatment with cabazitaxel, and a new scenario with the introduction of AA from the perspectives of the payers (HMOs) and service provider (infusion clinics). Pharmaceutical costs were based on official list price applying reimbursement inflators. Costs with adverse events and drug administration were obtained from published literature. Deterministic sensitivity analysis (DSA) was conducted to determine the impact of parameters on results. RESULTS: According to the model, a total of 5,098 patients were eligible for treatment with either cabazitaxel or AA over the three years of analysis. In the base case scenario, from the payers’ perspective the introduction of AA decreased total treatment costs of the target population by R$47,516,469. If reinvested on the treatment of mCRPC patients, these economic savings could allow for the treatment of 692 more patients with AA. For the service provider, assuming reimbursement inflator of 10% in cabazitaxel factory price, better financial results per patient are achieved in a scenario where reimbursement inflator of AA is set at 15% of factory price. In DSA, economic savings from the payers perspective ranged from R$12,454,979 (assuming mean duration of treatment with AA of 10 months) and R$118,637,890 (assuming 100% of market share for AA).  CONCLUSIONS: The introduction of AA may generate economic savings for both HMOs and infusion clinics, possibly allowing treatment of more patients with mCRPC previously treated with docetaxel.