OBJECTIVES: Biological drugs of intravenous (IV) and subcutaneous (SC) administration are of mandatory coverage by the private health insurances (PHIs) in Brazil for the treatment of psoriatic arthritis (PsA) and ankylosing spondylitis (AS). The purpose of this study is to compare the annual treatment cost of the biological drugs approved for spondyloarthritis in Brazil. METHODS: Four biological drugs are currently approved for spondyloarthritis treatment in Brazil: adalimumab (ADA), etanercept (ETN), golimumab (GOL) and infliximab (IFX). Published and extensive literature shows no difference in safety and efficacy among them, being equally recommended by the Brazilian Society of Rheumatology (SBR) Consensus. Therefore, a cost-minimization analysis was performed. Annual treatment costs were calculated for a patient of 70 kg, following doses/intervals defined in the products labels. Only drug acquisition costs were considered and prices were gathered from the official price list. Deterministic sensitivity analysis (DSA) was carried to determine the impact of weight parameter on results, since IFX dose is weight-dependent. RESULTS: GOL shows the lowest annual treatment cost for spondyloarthritis treatment in the private health system at R$38,212/patient/year, less than half of annual treatment cost with alternative options, regardless of administration route: ADA (R$85,807), ETN (R$77,998) and IFX (R$85,873). Hypothetical simulations show that GOL can treat the same number of patients by half of the budget or treat twice as patients at a same budget level compared to alternative options. The DSA shows that annual treatment cost with IFX can reach up to R$128,809 assuming a patient of 110 kg. CONCLUSIONS: GOL shows to be an option of great value to PHIs managers for spondyloarthritis management. In case GOL is chosen as preferred biological drug, it can bring important savings to PHIs or treat twice as patients compared to alternative options, with the convenience of a once a month SC dosage.