Continuous brachial plexus block is the technique of choice for postoperative shoulder pain treatment. The localization of the plexus is usually obtained drawing landmarks on the skin and using the electrical nerve stimulator; these and other different modalities are applied in order to reach safely and precisely nerve roots to be blocked with an anaesthetic solution. The Author presents a new anatomical perspective to guide the localization of the brachial plexus. It is shown how it is possible to detect the pathway of the brachial plexus from the cutaneous surface, linking between each other various landmarks: a) the apex of the scalene triangle, at the cross of a line leaving from the cricoid process and directed posterior to the posterior border of the sternocleidomastoid muscle, b) the midline of the clavicle c)the deltoid-pectoral sulcus d) the midpoint between the coracoid process and the chest profile e) the pulsation of the artery in the axylla. Following the guide of the so formed anesthetic line, is possible to place the needle, with a direction from distal to proximal, in a tangential route towards the interscalenic groove, thus allowing to perform a block of the plexus in a simple and efficacious way.