Central line-associated bloodstream infections (CLABSIs) are important hospital-acquired infections that are related to increased mortality in cardiac intensive care units (CICUs). To determine the risk factors for CLABSIs, a case-control study was conducted in the CICU of our hospital. Emergency surgery (odds ratio: 9.6, 95% confidence interval: 1.633-56.926) was the strongest risk factor comparing the case group (n=11) to the control group (n=22). In addition, the indwelling period was significantly longer in the case group than in the control group (median 9 days versus 7 days, p=0.004). An intervention for the insertion of central lines was then started, with 1) thorough use of chlorhexidine-impregnated dressings (also known as chlorhexidine patches, CHG patches) in the insertion of central lines before emergency surgery, and 2) exchange of the central line 7 days after emergency surgery. After the intervention, the CLABSI incidence rate decreased from 6.8 to 0.8/1,000 device-days. These data suggest the usefulness of CHG patches and the importance of the early exchange of central lines in the CICU in patients following emergency surgery.