OBJECTIVE To evaluate a new silver-impregnated multi-lumen central venous catheter for reducing catheter-related colonization in intensive care patients. METHODS Multicenter, prospective, randomized, controlled clinical study. METHODS Ten adult intensive care units (multidisciplinary, medical and surgical, university and nonuniversity hospitals) in eight institutions. METHODS A total of 577 patients who required 617 multi-lumen central venous catheters between November 2002 and April 2004 were studied. METHODS Intensive care adult patients requiring multi-lumen central venous catheters expected to remain in place for >or=3 days were randomly assigned to undergo insertion of silver-impregnated catheters (silver group) or standard catheters (standard group). Catheter colonization was defined as the growth of >or=1,000 colony-forming units in culture of the intravascular tip of the catheter by the vortexing method. Diagnosis of catheter-related infection was performed by an independent and blinded expert committee. RESULTS A total of 320 catheters were studied in the silver group and 297 in the standard group. Characteristics of the patients, insertion site, duration of catheterization (median, 11 vs. 10 days), and other risk factors for infection were similar in the two groups. Colonization of the catheter occurred in 47 (14.7%) vs. 36 (12.1%) catheters in the silver and the standard groups (p = .35), for an incidence of 11.2 and 9.4 per 1,000 catheter days, respectively. Catheter-related bloodstream infection was recorded in eight (2.5%) vs. eight (2.7%) catheters in the silver and the standard groups (p = .88), for an incidence of 1.9 and 2.1 per 1,000 catheter days, respectively. CONCLUSIONS The use of silver-impregnated multi-lumen catheters in adult intensive care patients is not associated with a lower rate of colonization than the use of standard multi-lumen catheters.