Coagulase-negative staphylococci, particularly methicillin-resistant strains of Staphylococcus epidermidis (MRSE), are common causes of hospital infections in Sweden today. In several studies, it has been shown that some strains of S. epidermidis are more widespread than others in a particular hospital. An enhanced ability to colonize human skin may possibly explain why certain strains spread epidemically. MRSE may be transmitted between patients by many possible routes, though it is difficult to determine which is most important. Direct and indirect contact transfer occur, as for other bacteria, but, unlike for most other bacteria, air dispersal on loosened skin scales is also very important. Another possible route of transmission is on the clothes of staff. To reduce spread of MRSE in hospitals, it is important that MRSE should not become a part of the resident flora of patients and staff. More investigations are needed, including studies of the effects of different systemic antibiotics on the microbial flora of the skin.