The indications to the positioning of central venous catheters (CVCs) are various: parenteral nutrition, chemotherapy, infusion of large amount of fluids or blood products, chronic access for hemodialysis, invasive measurement of hemodynamic variables. Infection is the most important clinical complication associated with the use of CVC, both in terms of incidence and of gravity. Despite the efforts for the optimization of the materials that are more and more biocompatible, the presence of a foreign body in the organism is an ideal substratum for the microbial colonization. The Catheter-Related-Bloodstream-Infections (CRBI) involve a pro-longation of recovery stay, the increase in costs of hospitalization and an increase in morbidity and mortality. The infections are caused by: Staphylococcus aureus and Staphylococcus epidermidis (60%), other bacteria (Enterococ-cus faecalis and Faecium, Pseudomonas aeruginosa; 25%) and among fungi by Candida albicans and Parapsilosis (15%). In order to prevent the CRBI it's important to follow some behavioural norms, both during the positioning of the catheter and in the subsequent assistance to the patient. In case of CRBI it is fundamental to make a sure diagnosis with the positivity for the same pathogen of 2 hemocultures obtained from CVC and from a peripheral vein and then with the microbiological analysis of the tip of the catheter, in order to carry out the specific antibiotic therapy.