The postmortem findings of the ventral roots and ventral horn cells of 15 Japanese cases of Guillain-Barré syndrome are reported. In 5 cases there was predominant axonal involvement with severe axon loss in the lumber ventral root. Eight cases showed predominantly segmental demyelination, and two cases were the intermediate form with both segmental and axonal changes. Macrophage invasion in the ventral roots predominantly occurred in the cases with axonal involvement. Large-sized motor neuron loss and reactive astrogliosis were also seen in the cases with axonal degeneration. These findings indicate that approximately 30% of Japanese autopsied cases were "axonal form", the incidence of which was higher than that reported in European and North American countries, but was lower than that in Chinese endemic acute motor axonal neuropathy.