There are no data on the prevalence and other epidemiologic characteristics of chronic symmetric polyneuropathy (CSP) in the community. This study was designed to assess the prevalence and risk factors of CSP in well-defined elderly (55 years and older) populations from two separate areas in Italy. Thirty-five general practitioners working in the two areas were invited to interview a random sample of patients requesting consultation. They used a pretested questionnaire which focused on selected symptoms of polyneuropathy, common risk factors for CSP, and current drug treatments. Patients giving affirmative answers to the questions on screening symptoms received a further clinical evaluation by a neurologist. Details are given of the general characteristics of the study areas and populations, the methods of case ascertainment, the validation of the screening instruments, and the results of a pilot study.