The following is a preliminary report of a new method of restoring function to paralyzed nerves, by anastomosis with analogous nerve trunks on the opposite side of the body. The patient herewith presented had an anastomosis between the healthy left brachial plexus and an almost completely paralyzed right brachial plexus, fifteen months after an attack of anterior poliomyelitis. In this case the operation has been followed by no demonstrable injury to the left brachial plexus, but by a rapid and very decided gain of power in the right hand, forearm and shoulder. The operative treatment of brachial palsy in the past has dealt chiefly with those forms of paralysis in which the lesion involves directly the nerve fibers of the brachial plexus. Thus in brachial birth palsy, and in those forms occurring later in life from traumatism of the plexus, encouraging results have been obtained by excluding, by means of