As a result of the high rate of infection, the NKF-K/DOQI guidelines recommended that an uncuffed catheter (UC) should not be used for longer than three weeks. However, the findings of the Dialysis Outcomes and Practice Patterns Study recognized that 48% of new hemodialysis patients in the US and 75% in Europe used UC for temporary access during arteriovenous fistula or graft maturation. The antibiotic lock technique (ALT) has been recommended to prevent catheter-related bacteremia (CRB). Here, we prospectively evaluated the efficacy of catheter-restricted filling using an antibiotic lock solution in preventing CRB. A total of 120 new hemodialysis patients requiring a temporary catheter while waiting for placement and maturation of an arteriovenous fistula or graft were enrolled in this study. Patients with a UC were randomly assigned to receive either an antibiotic-heparin lock solution (antibiotic group: cefazolin 10 mg/ml, gentamicin 5 mg/ml, heparin 1000 U/ml) or a heparin lock solution (no-antibiotic group: heparin 1000 U/ml) as a catheter lock solution during the interdialytic period. The end point of the trial was CRB. CRB developed in seven (11.7%) patients in the no-antibiotic group (Staphylococcus aureus, two; Staphylococcus epidermidis, five) whereas only one patient in the antibiotic group had S. aureus bacteremia. CRB rates per 1000 catheter-days were 0.44 in the antibiotic group versus 3.12 in the no-antibiotic group (P=0.031). Kaplan-Meier analysis also showed that mean CRB-free catheter survival of 59 days (95% CI, 58-61 days) in the antibiotic group was greater than that in the no-antibiotic group (55 days; 95% CI, 50-59 days). The results suggest that ALT may be a beneficial means of reducing the CRB rate in hemodialysis patients with UC.