This study was performed to evaluate associations between organisational characteristics, routine practices and the incidence densities of central venous catheter-associated bloodstream infections (CVC-BSI rates) in European intensive care units (ICUs) as part of the HELICS project (Hospitals in Europe Link for Infection Control through Surveillance). Questionnaires were sent to ICUs participating in the national nosocomial infection surveillance networks in 2004. The national networks were asked for the CVC-BSI rates of the ICUs participating for the time period 2003--2004. Univariate and multivariate risk factor analyses were performed to identify which practices had the greatest impact on CVC-BSI rates. A total of 526 ICUs from 10 countries sent data on organisational characteristics and practices, demonstrating wide variation in care. CVC-BSI rates were also provided for 288 ICUs from five countries. This made it possible to include 1383444 patient days, 969897 CVC days and 1935 CVC-BSI cases in the analysis. Adjusted logistic regression analysis showed that the categorical variables of country [odds ratio (OR) varying per country from OR: 2.3; 95% confidence interval (CI): 0.5-10.2; to OR: 12.8; 95% CI: 4.4-37.5; in reference to the country with the lowest CVC-BSI rates] and type of hospital 'university' (OR: 2.08; 95% CI: 1.02-4.25) were independent risk factors for high CVC-BSI rates. Substantial variation existed in CVC-BSI prevention activities, surveillance methods and estimated CVC-BSI rates among the European countries. Differences in cultural, social and legal perspectives as well as differences between healthcare systems are crucial in explaining these differences.