Central venous pressure measurement, prolonged intravenous nutrition, massive and rapid fluid replacement, infusion of hypertonic and cytotoxic solutions, and the use of percutaneous pacemakers have all made catheterization of the great veins of the neck and superior mediastinum a common hospital procedure. A detailed knowledge of the internal jugular, subclavian and brachiocephalic veins is therefore of considerable importance – especially their surface markings and the position of adjacent structures which may inadvertently be damaged in these procedures.