Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects symmetrically multiple joints. Recent therapeutic strategy has been focusing on the symptoms of the disease and the ways to prevent its progression as early as possible. Thus, early diagnosis is crucial since early therapy with disease-modifying anti-rheumatic drugs reduces the severity of joint damage. It is the early period of the development of the disease that a specific and sensitive serologic test is needed. The RA patient sera contains a lot of antibodies. Some of them are not specific for RA occurring also in other diseases, others are highly specific and detectable only in rheumatoid arthritis. Rheumatoid factor (RF) is a very sensitive but poorly specific marker which makes it rather an unsuitable antibody for rheumatoid arthritis. RA-specific antibodies can be very useful for early diagnosis and prognosis of the disease. Among the antibodies described in recent years the most promising candidates are the autoantibodies to antigens containing one or more than one citrulline residues (cyclic citrulline peptides, CCP) - the anti-CCP antibodies. They have been shown in recent research to play an important role in the diagnosis, prognosis and therapeutic approach to patients with RA. Their high specificity, the ability to diagnose RA early in its development and distinguish it from other nonerosive type of arthritis, make the anti-CCP a key serologic marker in the future.