The fact that chronic renal failure may be associated with polyneuropathy is not generally appreciated and is practically undocumented in the medical literature. Yet, in the past five years we have studied four patients, both clinically and pathologically, in which just such a relationship existed, and it seems warranted, therefore, to report our observations. It should be emphasized that each of these patients was afflicted with primary Received for publication Dec. 10, 1962. From the Neurology Service, the Charles S. Kubik Laboratory for Neuropathology, and the James Homer Wright Laboratory of Pathology, Massachusetts General Hospital, and the Department of Neurology and Psychiatry (Neuropathology), Harvard Medical School, Boston. This work was aided in part by a Training Grant (2B-5075) and Research Grant (B-1906), National Institute of Neurological Diseases and Blindness, United States Public Health Service. renal disease and in each a serious degree of renal failure had existed for many years