Case of a 58-year-old patient diagnosed as having mycosis fungoides (MF) who presented with sensory ataxia, limbs weakness and neurophysiological and laboratory signs indicative of autoimmune chronic mixed axonal-demyelinating sensory-motor polyradicular neuropathy. The possibility that MF may be associated with an immunomediated peripheral neuropathy, even in the absence of a direct invasion of the nerves and widespread visceral involvement, should be considered.