Catheter-related infections are one of the most serious complications of TPN therapy. Nurses have important responsibilities in the care of patients who are receiving TPN. This quasi-experimental study was conducted for the purpose of investigating the effectiveness of an educational intervention on changing nursing practice and preventing catheter-related infections in patients receiving total parenteral nutrition. The nurses' practice and the colonisation rate of control and comparative group patients in the surgical clinics of Hacettepe University Hospital (Turkey), and related variables were examined before and after an educational intervention. The findings of the study indicate that the intervention was successful in improving appropriate nursing practice, mean scores of nurses' practices were 45.7 before and 66.5 after the intervention (p < 0.05). The rate of microorganism colonisation was also decreased but statistical analysis demonstrated no association between nursing practices and microorganism colonisation of catheter cultures. (C) 2000 Elsevier Science Ltd. All rights reserved.