Central venous catheterization is a ubiquitous procedure in intensive care units and is mainly used for drug administration, hemodynamic monitoring and hemodialysis. Only in US more than five million catheters are inserted annually. One of the main complications associated to central venous lines are the mechanical ones, i.e. arterial puncture, bleeding and hematoma formation, which varies between 5% and 19%. The use of real-time ultrasonography to accomplish central venous catheterization was associated to a drastic reduction in complication rates, and when performed by trained personnel, some series show complications rates <1%, even in patients with coagulopathy.