Three biological agents have proved to be better than placebo in the management of active RA. None of them proved to be better than MTX when used as single drug therapy. Combination of any of these three drugs with MTX has proved to be more beneficial than MTX administered alone. Special care should be taken in the surveillance of severe infections, autoimmunity and neoplasias in patients treated with these drugs, especially screening for TB prior to starting therapy. These are drugs with a potentially high cost for health systems. In those countries where studies were conducted on their cost-effectiveness, these treatments did not prove to be cost-effective or their cost-effectiveness was at the limit of internationally accepted standards. That is why, in countries where these drugs are covered, they are specifically used in those selected subgroups of patients with active RA who have not adequately responded to conventional treatment with MTX or who have not tolerated it.