Seven patients with subacute sensory neuropathy are described and the findings in 29 previously reported patients are reviewed. The presence of this characteristic neurological disorder strongly suggests an accompanying neoplasm. Five of 7 patients had cancer, and 4 died. Autopsy was performed on 3, and pathological analysis revealed inflammation and degeneration of dorsal root ganglia and degeneration of posterior roots and posterior columns of the spinal cord. The dorsal root ganglion was biopsied in 4 patients and showed similar inflammatory lesions. Electron microscopical studies showed inflammation and neuronal degeneration. No viral particles were seen. Viral cultures of the biopsied ganglia from 4 patients were negative. Antineuronal antibodies were not detected in 2 patients. The cause of this syndrome is unknown, and no treatment has been successful.