The use of chlorhexidine gluconate solution for vascular catheter insertion site care reduces the risk of catheter-related bloodstream infection by one-half, compared with povidone iodine. Our objective was to evaluate the cost-effectiveness of chlorhexidine gluconate versus povidone iodine. We used data from randomized, controlled trials, meta-analyses, and epidemiologic studies to construct a decision analysis model. We estimated that use of chlorhexidine, rather than povidone, for central catheter site care resulted in a 1.6% decrease in the incidence of catheter-related bloodstream infection, a 0.23% decrease in the incidence of death, and savings of 113 dollars per catheter used. For peripheral catheter site care, the results were similar, although the differences were smaller. The results were found to be robust on multivariate sensitivity analyses. Use of chlorhexidine gluconate in place of the current standard solution for vascular catheter site care is a simple and cost-effective method of improving patient safety in the hospital setting.