One hundred sixteen subclavian hemodialysis catheter placements in 88 patients were prospectively evaluated for catheter-related infections. Semiquantitative culture techniques and a rigid infection control protocol were used. The overall catheter colonization rate was 21.6% and catheter-associated bacteremia occurred in 9.4%. Catheters removed from febrile patients had much higher colonization (48.3%) and bacteremia (34.5%) rates. In a randomized study comparing infection rates in catheters tunneled subcutaneously or not tunneled, there was no significant difference in the incidence of infection. Catheters inserted over a guidewire to replace clotted or malfunctioning catheters were not associated with higher infection rates.