Seventeen cases of peripheral neuropathy with plasmocytic proliferation were grouped together to analyze the clinical manifestations and evolution of this association of symptoms. The plasmocytic proliferation was 5 times that of multiple myeloma, 9 times that of a solitary bone plasmacytoma and 3 times that of a solitary plasmacytoma. The follow-up lasted 1 to 18 years (mean, 8 years) for solitary plasmacytomas. Other cutaneous and endocrinological symptoms, organomegaly and edema were sometimes present. The evolution was relatively severe, except in 6 patients whose solitary plasmacytomas were successfully treated with radiation. Six patients died 2 to 8 years (mean, 5 years) after the onset of neuropathy as a result of a progression of the neuropathy and/or anasarca (4 cases), or acute leukemia (2 cases) abetted by long-term chemotherapy. The therapeutic approaches available, the nature of the plasmocytic proliferation and its association with the neuropathy and the other symptoms are discussed.