We reported clinical, electrophysiological and pathological findings in 10 patients with acquired, slowly progressive sensory neuropathy. Group I patients which had delayed sensory nerve conduction velocities (SNCV) or no response of SCV in electrophysiological studies were observed to have marked deep sensory disturbances. On the other hand, Group II who had abnormalities of both SNCV and motor nerve conduction velocities electrophysiologically has tendency to show superficial sensory disturbances more dominantly than that of deep sensation. Histological findings of biopsied sural nerve in Group I were mainly composed of diminution of large myelinated fibers, in Group II the diminution of large myelinated fibers with decreased unmyelinated fibers were observed. However, there were no significant difference between Group I and Group II in the quantitative analysis of myelinated fibers. There were no definite tendency under the basic disease or background factors of these 10 patients. Only 3 of these 10 patients had immunological abnormalities such as RA factors or antinuclear antibodies.