Emil von Behring's serum therapy for diphtheria was the first therapeutic use of antibodies. More than 100 years later, a new era in the treatment of rheumatic diseases began in 1998 with the approval of infliximab, an antibody directed against tumor necrosis factor alpha (TNF alpha). The special feature of antibody therapy is the ability to bind and neutralize antigens in a highly specific manner. In addition, target cells can be eliminated by activation of the immune system. These properties of the immune system are exploited in rheumatology to eliminate inflammatory cytokines or antibody-producing B lymphocytes. The tolerability is usually good but potential side effects, such as reactivation of tuberculosis with anti-TNF alpha treatment must be considered. Currently, 20 different antibodies and fusion proteins have been approved in Germany for the treatment of various inflammatory rheumatic diseases. Biosimilars can contribute to a price reduction after the patent protection expires. Many additional target antigens are being investigated and further structural innovations (e.g., bispecific antibodies, nanobodies or coupling with small molecules) are being developed.