OBJECTIVES: Rituximab is an anti-CD20 monoclonal antibody with demonstrated efficacy for patients with rheumatoid arthritis who had inadequate response to anti-TNF therapies (Cohen et al. 2005). The primary objective of this analysis was to estimate the total cost of rituximab therapy and to compare it with infliximab, adalimumab and etanercept under a private payer perspective in Brazil. A budget impact analysis (BIA) of the incorporation of rituximab was also performed. METHODS: We assumed the same efficacy for the comparators as there is not any head-to-head clinical trial available until date and indirect comparisons showed higher ACR response rates for Mabthera. Direct annual medical costs for biological drugs, IV administration, weekly metotrexate (MTX) and routine exams were taken from a Delphi panel with Brazilian rheumatologists. Base case dosages considered were: rituximab (2g at every 8 months), infliximab (4mg/kg at weeks 0, 2, 6 and then at every 8 weeks); adalimumab (40mg every other week) and etanercept (50mg per week). Local administration costs were obtained from Scheinberg et al. (2005). Costs were reported in 2007 Brazilian Reais and discounted at a 5% rate in the BIA. Therapies were evaluated using a 5-year horizon. In order to assess uncertainty, one and two-way sensitivity analyses were also performed. RESULTS: In the base case scenario, rituximab therapy resulted in a total annual cost of R$ 45,647 per patient. Total annual costs per patient for infliximab, adalimumab and etanercept were R$ 78,638; R$ 89,943 and R$ 119,170 respectively. In the BIA, rituximab therapy resulted in total savings of R$ 91,006,061 in 5 years. Results were sensitive to dosage schedule (rituximab and infliximab) and drug acquisition costs. CONCLUSION: Results suggest that therapy with rituximab is a cost-saving alternative for patients with rheumatoid arthritis in the Brazilian private Healthcare system, unfettering resources for other disease areas.