Experience gained with supraclavicular anonyma (brachiocephalica) catherizations carried out on more than 2,500 patients in an emergency and for prolonged infusion therapy is explained and discussed in the following on the bases of 800 registered tappings. A detailed description and discussion is given of the technical and methodical aspects of applying the Seldinger method and a constant catheter length, and in using a recently developed catheter which has the advantage of letter fixation; The only clinical complications observed during an average infusion time of six days was pneumothorax in 1.2% of the tappings and phlebitis in 0.9% of the catherizations. For vena anonyma tapping, the particular advantages are the easy accessibility of the vessel in every state of blood circulation at a high rate of 95%, the non-existence of false positions, the excellent catheter compatibility, the possibility of recatheterization, the possibility of optimum fixation, the safety in nursing, and the unrestricted mobility of the patient.