We examined antibodies against 10 heat shock proteins (HSPs) in cerebrospinal fluids (CSF) and sera from patients with Guillain-Barré syndrome (GBS). Significantly higher IgG antibody titers against HSP27, HSP60, HSP70 and HSP90 family, including mycobacterial HSP65 and Escherichia coli GroEL, were found in CSF from GBS patients as compared with motor neuron disease. Serum IgG antibodies against each HSP showed no difference between GBS patients and normal controls. GBS seems to be induced by reactive autoimmune responses frequently triggered by infections. The CSF antibodies against HSPs may modify the immune responses and/or cell-protective functions of HSPs in the pathophysiology of GBS.