OBJECTIVES: Rheumatoid arthritis (RA) is a systemic autoimmune disease which affects 0.5% of the population in developing countries. In Brazilian public healthcare system (SUS) infliximab, etanercept, adalimumab, golimumab, certolizumab (anti-TNF), abatacept (T-lymphocyte activation inhibitor) and tocilizumab (IL-6 inhibitor) are available as biological treatment. However, only anti-TNF therapies are indicated as standard of care for first-line biologic therapy. As tocilizumab is a known effective and cost-saving drug for this indication, the present study aims to evaluate the budget impact of its inclusion in public RA biologics first-line setting.  METHODS: A model was developed in order to assess the budget impact of tocilizumab reimbursement as a first-line biological therapy under SUS perspective from 2014-2018. Only expenditures with biologics were accounted according to posology presented in Brazilian Ministry of Health RA Guideline considering a mean 67kg-weighted patient. Prices were obtained from public disclosures. Forecasts were made pursuant to government sources (IBGE, DataSUS) and market research-based data. Different mix scenarios based on varying growth rate of tocilizumab usage were assessed to evaluate total savings. A two-way sensitivity analysis was conducted changing diagnosis and biologics use rates. Costs were reported in Brazilian currency (BRL1.00~USD0.51 Feb2013). RESULTS: Annual costs per patient were BRL20,002, BRL25,625, BRL26,899, BRL18,330, BRL22,386, BRL15,232 and BRL27,391, for tocilizumab, etanercept, adalimumab, infliximab, abatacept, certolizumab and golimumab, respectively. Concerning different tocilizumab public usage scenarios, if it reaches 20% in 2018, savings could sum BRL143,058,554 (-2.8%) in the analyzed period. Nonetheless by achieving a 40% usage savings would be even higher resulting in a potential BRL318,643,978 (-6.3%) economy in the same period. Sensitivity analysis showed savings ranges of: BRL101,782,493-BRL262,029,470 (20% usage scenario) and BRL228,085,067-BRL579,597,311 (40% usage scenario). CONCLUSIONS: The public inclusion of tocilizumab in 2014 as a RA first-line biologic therapy and its usage enhance would result in increasingly savings arousing significant impacts in public healthcare budget.