A series of 508 patients with traction injuries of the brachial plexus (birth trauma excluded) has been investigated over a period of 11 years. Severe cases with root avulsions, ruptures of nervous pathways or severe disorganization of funiculi do not heal spontaneously or heal poorly. Whether these patients can benefit from modern microsurgical techniques (neurolyses, autologous nerve grafts and neurotizations with intercostal or other nerves) is presently under investigation. Operations were performed on 164 patients of whom 114 had root avulsions and 16 had 2 level injuries. Surgical treatment was planned according to the severity of the lesion. In about 10% no reconstruction was possible, or was of doubtful value. There is a striking difference in results of supraclavicular and distal, infraclavicular lesions. Only 55% positive of 58 patients of the first group were improved while 85% of 20 patients of the second group were benefited to some extent. None of the patients belonging to the first or second group recovered hand intrinsic function if pathways coming from C8 and T1 were injures. None recovered tactile gnosis. The effect on pain was sometimes ameliorative, but generally unpredictable.