The presence of polyglucosan bodies in sural nerves collected over a 16-year period was studied in relation to age, sex, presence of polyneuropathy, and concomitant presence of central nervous system disorder. Polyglucosan bodies have been seen in only one patient without a polyneuropathy. This patient was suffering from Lafora's disease. In all other sural nerves positive for polyglucosan bodies a polyneuropathy was present. Within this group the prevalence of polyglucosan bodies was positively correlated with age, and if a central nervous system disorder was associated, this prevalence was more distinct. With semiquantitative measurements of the surface of polyglucosan bodies a significant correlation was found between age and percentage of large bodies.