The aim of this retrospective study was to assess the incidence and aetiology of central and peripheral venous catheter (C/PVC) infections during a 2-year period (1999-2000) and to determine the susceptibility of isolated microorganisms to various antimicrobial agents. Catheter tips were processed using the semiquantitative method and blood cultures were performed with the BacT/Alert automated system. Antibiotic susceptibilities were performed by disk agar diffusion and MICs were determined by Etest, according to NCCLS standards. During the study period, samples from 1039 C/PVC infections were evaluated, yielding 384 (37.0%) positive cultures. Blood cultures were also available from 274 patients, of which 155 (56.6%) yielded the same microorganism as from the catheter. No bloodstream infections were detected in 104 C/PVC-positive cases. Methicillin-resistant coagulase-negative staphylococci were the most frequent isolates, followed by Gram-negative bacteria, especially Pseudomonas aeruginosa. Resistance to glycopeptides among staphylococci and enterococci was not detected, whereas 60% of Gram-negative bacilli were resistant to beta-lactams.