Sensory neuropathies, particularly trigeminal neuropathy, have been recognized as neurological complications of Sjögren's syndrome, but the pathogenesis has not been established. We describe a woman with primary Sjögren's syndrome who developed a progressive debilitating subacute sensory neuronopathy. Results of electrophysiological studies were consistent with involvement of the trigeminal and dorsal root ganglia. A thoracic dorsal root ganglion biopsy showed lymphocytic infiltration and degeneration of ganglion cells. We believe that this is the first description of biopsy-documented dorsal root ganglionitis in a subacute sensory neuronopathy associated with Sjögren's syndrome and that the finding suggests an immunopathogenic basis.