We attempted to elucidate the nature of the nerve fiber degeneration and clinical features of six Chinese patients with lung cancer preceded by sensory disturbances, with special emphasis put on the morphometric analysis of the nerve fibers of the sural nerve obtained on biopsy. The patients were all male and ranged from thirty-nine to sixty-seven years of age on admission. They all complained of paresthesia as the initial symptom in the distal portion of both extremities, two to seventy-two months prior to the diagnosis of the cancer. The paresthesia was slowly progressive and mild to moderate in severity without obvious subjective sensory loss. Four patients showed diminished Achilles reflex and decreased vibration sensation at the lateral malleolus. Morphometric evaluation of the sural nerve revealed that the loss of myelinated and unmyelinated fibers was not frequent and the increase in the density of the small myelinated fibers was prominent, suggesting the presence of axonal atrophy. Therefore, it was concluded that the histologic findings of our patients are different from those found in subacute carcinomatous sensory neuropathy associated with lung cancer that is well established clinically and histologically, and are compatible with those of axonal atrophy, partly related to unknown remote effects of cancer.