Rheumatoid arthritis (RA) is the most frequent form of chronic polyarthritis, affecting 0.5-1% of adults worldwide. In recent years there have been important advances in the pathogenesis of RA, together with new diagnostic and therapeutic insights. Early diagnosis is essential in order to prevent joint damage and improve the prognosis and quality of life of patients with RA. New classification diagnostic criteria have been proposed to achieve this objective. New therapeutic strategies have proved to be effective, including early and better use of synthetic disease-modifying anti-rheumatic drugs (DMARDS), mainly methotrexate, and a treat-to-target strategy focusing on achieving remission and with tight control of the disease. In the last decade, the introduction of various biological agents in the therapeutic armamentarium of RA has changed the disease prognosis, although no definite cure is currently possible. In this chapter, we present an overview of recent advances in the epidemiology, diagnosis, prognosis and treatment of this severe but treatable disease.