Central venous catheterisation under two-dimensional ultrasound (US) guidance has been proved to be quicker and safer than the classical landmark method in both adults and children. In the literature US guidance with sterile dressing of the probe is the 'gold-standard'. Another way to use US is simple preoperative US location followed either by blind puncture, either by US guided puncture when difficulties are expected: small infants (<15 kg), small diameter or collapses of the vein, multiple unsuccessful attempts during blind technique. Ideal location of the tip of central venous catheters is no more controversial but can depend on age and weight. In 2002 a French agency (Afssaps) study showed that the risk of perforation and tamponade was especially high in small weight prematures with 27 gauge polyurethane catheters when tip was located in the cardiac cavities. In children and adults venous thrombosis and catheter malfunction are closely related to short catheters whose tip is above T3-T4. Excepted polyurethane catheters in small weight prematures, the best location of long-term central venous catheters tip is the superior vena cava-right auricle junction. At this time routine antithrombotic prophylaxis is not recommended for children with long-term central venous catheters.