Coagulase-negative staphylococci, long considered to be harmless commensals or contaminants, have emerged as major pathogens as medical technology has advanced. They are a major cause of intravenous-catheter-associated bacteremia, endocarditis, otitis media, and infection of joint prostheses, vascular grafts, cardiac pacemakers, cerebrospinal fluid shunts, postoperative wounds, the urinary tract, and the eye. Therapy includes removal of infected foreign bodies and administration of appropriate antimicrobial agents.