The Guillain-Barre Sydrome (GBS) is post-infectious autoimmune disease and it could be caused by auto-antibodies produced after infections. Mycoplasma pneumoniae is one of rare cause of GBS and known to be associated with antibody to galactocerebroside (GalC) which is a major neutral glycolipid constituent of myelin. We report a case of GBS with immunoglobulin M GalC antibody after M. pneumoniae infection.