The majority of central venous line-associated infections are caused by organisms on the skin near the exit site gaining access to the intravascular segment of the catheter. A variety of strategies have been used in an effort to reduce catheter contamination, but one innovation--the semipermeable transparent dressing--may actually increase infection risk. On the other hand, new catheter materials and designs probably reduce the risk. There are only a limited number of well-designed studies of the increasingly popular totally implantable catheter system and the multilumen line, but it appears that the former is associated with a low rate of infection, while the latter may be more hazardous than the single-lumen line.