The PNS is an immunocompetent organ. The participating cellular and humoral elements in the local immune circuitry have been identified. A number of acute and chronic neuropathies appear to result from disturbed immune homeostasis. The model disorder EAN has been useful in examining the induction, amplification and effector phase of autoimmune responses to peripheral nerve antigens. Potential autoantigens contained in the myelin sheath and on the axolemma have been characterized. Thus, the recent years have seen a rapid growth of information concerning the pathogenesis of the important group of immune-mediated neuropathies. It can be anticipated that the better understanding of the principal mechanisms of autoimmunity in the PNS will aid in the development of more specific and efficacious treatments for these crippling diseases.