The aim of this study was to analyse the effectiveness of teicoplanin versus vancomycin lock therapy in the treatment of coagulase-negative staphylococci (CoNS) venous access port-related bloodstream infection (BSI). The study included 44 consecutive patients during a 36-month prospective case-series study. The primary endpoint was failure to cure. Treatment was successful in 39 patients. At the end of the study, the cumulative port survival rate was 100% in the teicoplanin lock group compared with 77% in the vancomycin lock group (P=0.06). In the Cox regression analysis, fever beyond 48 h of treatment was a significant predictor of treatment failure (P=0.02). Use of vancomycin or teicoplanin locks had an effectiveness of 88.6% in the treatment of CoNS port-related BSI. Teicoplanin locks reduced the failure rate from 18.5% to 0% compared with vancomycin locks. The presence of fever after beginning antimicrobial lock therapy was associated with treatment failure.