Rheumatoid arthritis (RA) is a common systemic, inflammatory, rheumatic disease of unknown etiology manifest by a chronic symmetric polyarthritis, particularly involving the small distal joints. Pathogenesis may involve inappropriate T-cell activation or lack of appropriate inhibition, although newer theories center on the importance of cytokines and membrane proteins that signal T-cells. Diagnosis is predicated on clinical assessment rather than extensive testing or exclusion of other illnesses, although well-known mimics of RA should be considered. The presence of objective synovitis in a "rheumatoid distribution" lasting more than 6 weeks is required for confident diagnosis. Treatment should be directed at maintaining function, reducing pain and preventing irreversible joint damage. Options include nonpharmacologic therapy, such as physical and occupational therapy, pharmacologic options such as analgesics, antiinflammatory therapies and second-line agents (or disease-modifying agents for rheumatic disease, DMARDs) and surgery. Newer approaches, including "biologics" aimed at interrupting cytokine effects and combinations of second-line agents, offer exciting potential for improving outcomes in RA. The prognosis of RA is highly variable and not reliably predictable in the individual patient early in disease.