The symptomatology of reflex sympathetic dystrophy (RSD), a diagnostic term which today includes causalgia and M. Sudeck, is characterized clinically by a triad of autonomic (sympathetic), motor and sensory disturbances. They develop following a noxious event--though independent of its nature and location--in a generalized distribution pattern at the distal site of the affected extremity. Pathophysiologically, a complex disturbance of the sympathetic vasoconstrictor system is involved, which mediates the dominant symptoms of RSD, namely the spontaneous pain and the swelling. This disturbance is thought to be initiated by nociceptive impulses, occurring in conjunction with the preceding noxious event, and to be maintained reflexly, in a form of a vicious circle, by means of the typical pain sensation accompanying the RSD-syndrome. From these ideas, an important part of the RSD therapy is deduced; i.e. the early interruption of the neuronal sympathetic activity by means of a sympathetic blockade. Such a blockade can interrupt the pain and at the same time also the vicious circle of RSD. Altogether, for the RSD syndrome there are relevant neurological aspects with respect to its clinical symptomatology, its pathophysiology and its therapy.