A 39 year old man presenting multifocal demyelinating neuropathy (MFDN) is reported. Fifteen days before onset he had been vaccinated with 75 IU of tetanus toxoid. Although recent histories of vaccination or viral infection support the immunological hypothesis proposed for chronic acquired demyelinating neuropathies (CADN) it is reported for the first time in MFDN, suggesting that MFDN and CADN may share common pathophysiological mechanisms.