Eleven patients with chronic progressive sensory ataxic neuropathy were examined clinicopathologically. Three cases were associated with primary Sjögren's syndrome (SS-SAN) and the others were considered to be idiopathic (ISAN). The major clinical symptom in both was loss of proprioceptive and kinesthetic sensation with some impairment of superficial sensation, with multifocal and asymmetrical distribution and progression. The truncal and trigeminal nerves were frequently involved. The motor system was substantially preserved. These somatic sensory and motor symptoms did not differ between ISAN and SS-SAN, but autonomic nervous system signs were more frequent in SS-SAN. Polyclonal elevations of serum IgG and/or IgA were seen in 8 patients. One autopsied case with ISAN combined with previous reports suggested that systemic T- and B-cell infiltration into the nervous tissues, as well as a wide variety of the visceral organs, may be a common finding in ISAN and SS-SAN, and could participate in the cause of this neuropathy and polyclonal hypergammaglobulinaemia.