Objective: To determine the rates of colonization and infection related to central venous catheter (CVC), the causative microorganisms, and the influence of various factors. Methods: From June to August 1993, all CVC in 4 Intensive Care Units were evaluated from their insertion to removaL Data were collected by 3 nurses. Blood and catheter tips were cultured. Results: Of 84 catheters, 29.8% were colonized, 9.5% of patients showed evidence of local infection, and 4.8% had primary bloodstream infections. The internal jugular vein was the most common site for catheter insertion (81%). Causes of removal were: end of need (48.3%), suspected infection (23.3%), malfunction (20%), routine change (8.3%). Among removals because of suspected infection, 50% presented evidence of local infection, 43% were colonized(>15cfu), but there were no bloodstream infections. The average time of catheter use for those which became colonized was longer than for catheters that did not become colonized (p=0.008). The average time of catheter use associated with removal for infection (local and bloodstream) was longer than for removal for other reasons (p=0.042). Among colonized catheters, 16% developed bloodstream infection and 20% local infection. Immunosupressive drugs, cancer, diabetes mellitus, HIV-infection, and neutropenia were not associated with infection or colonization. The most common microorganisms were gram-negative rods and S.aureus. Conclusions: The duration of venous catheter use increased the risk of colonization and infection. This observation suggests that physicians must strive for the shortest time of use of venous catheters, but it does not indicate a need for routine central venous catheter removal.