In elderly patients, peripheral neuropathies are common and may lead to disability. In order to investigate the relative incidence of different polyneuropathies in the elderly focusing on the contribution of nerve biopsy to their diagnosis, the authors studied 74 patients over 65 years of age with clinical, laboratory, electrophysiological, and sural nerve biopsy findings of different types of polyneuropathy. Vasculitic polyneuropathy seemed to be the most common cause of disabling neuropathy in the elderly, followed by paraneoplasia and diabetes. The possible diagnosis of idiopathic axonal neuropathy in the nine cases with neuropathy of unknown origin is discussed.