Infection is a frequent complication in rheumatoid arthritis (RA) and other autoimmune diseases. Since 2000, the spectrum of therapeutic possibilities (ie, biologic agents) for treating RA has expanded rapidly and many safety reports of patients treated with these drugs have been published. In most studies, biologics are associated with an increased incidence of infections with the use of tumor necrosis factor antagonists. Reported risks for developing infection differ among studies. This article provides an overview of which studies the authors consider the most relevant.