There have been no reported studies specifically devoted to the Guillain-Barré syndrome in elderly patients. The survey reported in this paper investigated the manifestations of the disease in older patients and compared them with those seen in younger patients. All adult patients with an established diagnosis of Guillain-Barré syndrome admitted over 9 years to a Regional Referral Centre providing services for a population of 543,213 were identified and studied. Fifteen patients were over the age of 60 years and 21 between 19 and 60 years of age. Antecedent illnesses and, in particular, gastro-intestinal symptoms were reported less frequently in older patients. Where there was an antecedent illness, this was of shorter duration in elderly subjects. Neurological symptoms related to peripheral nerve damage, such as paraesthesiae, myalgia, backage and an inability to stand, occurred with a similar frequency in both age groups. Double vision and facial weakness, however, occurred less often in older patients, and cerebellar features were not encountered in the older age group. The cerebrospinal fluid immunoglobulin abnormality was more marked in the elderly. The interval between onset and peak severity was shorter in elderly patients. The duration of hospital stay was significantly greater in the elderly, though the overall prognosis was similar in both age groups. There was only one death in each group. The incidence of the Guillain-Barré syndrome in the elderly was higher than in subjects aged 19-60 years, but this difference was not significant. Although it may present with equal severity in both old and young, it carries a similar prognosis in the old and must be as vigorously managed as in younger patien