An investigation is reported of the prevalence of keratoconjunctivitis sicca and xerostomia and of serum autoantibodies in 122 elderly subjects over 80 years of age. Keratoconjunctivitis sicca and xerostomia were found with increased frequency, and in addition many patients had diminished tear secretion with biomicroscopy evidence of punctate or filamentary keratitis. Surprisingly no association was found between any of the autoantibodies tested, which included rheumatoid and antinudear factors, smooth muscle, mitochondrial, salivary duct and non-tissue specific precipitins and thyroid, gastric parietal cell and adrenal antibodies, and the presence of keratoconjunctivitis sicca or xerostomia. This suggests that keratoconjunctivitis sicca and xerostomia in the elderly probably result from primary acinar atrophy rather than chronic inflammation associated with an autoimmune process; Histological studies are required to clarify this point.