Rheumatoid arthritis (RA) and juvenile idiopathic/rheumatoid arthritis (JIA) are chronic, inflammatory, systemic, autoimmune diseases characterized by chronic arthritis leading to progressive joint erosions. The individual functional and social impact of rheumatoid arthritis is of great importance. Disability and joint damage occur rapidly and early in the course of the disease. The remarkably improved outcomes have been achieved initiating biologic therapy with close monitoring of disease progression. Biologic agents are drugs, usually proteins, which can influence chronic immune dysregulation resulting in chronic arthritis. According to the mechanism of action these drugs include: 1) anti-TNF drugs (etanercept, infiximab, adalimumab); 2) IL-1 blocking drugs (anakinra); 3) IL-6 blocking drugs (tocilizumab); 4) agents blocking selective co-stimulation modulation (abatacept); 5) CD 20 blocking drugs (rituximab). Biologics targeting TNF-alpha with methotrexate have revolutionized the treatment of RA, producing significant improvement in clinical, radiographic, and functional outcomes not seen previously. The new concept of rheumatoid arthritis treatment defines early diagnosis, early aggressive therapy with optimal doses of disease modifying antirheumatic drugs (DMARDs) and, if no improvement has been achieved during six months, early introduction of biologic drugs. The three-year experience of biologic therapy in Serbia has shown a positive effect on disease outcome.