Carbohydrate epitopes of glycoconjugates are expressed on sensory neurons of dorsal root ganglion (DRG). A possible role of antibodies directed at carbohydrate determinants of the glycoconjugates has been suggested in some patients with sensory neuropathy. We investigated expression of blood group antigen-related epitopes in human DRG immunohistochemically using monoclonal antibodies to A, B, and H antigens. A blood group B determinant [Gal alpha 1-3(Fuc alpha 1-2)Gal beta-]-related glycoepitope was demonstrated in the neurons and surrounding satellite cells of DRG obtained from subjects with any ABO blood group phenotype. The treatment with trypsin or chloroform/methanol prior to the immunostaining suggested that the glycoconjugate exhibiting the blood group B determinant-related epitope consisted mainly of glycoprotein and included glycolipid. The glycoconjugates with the blood group B determinant-related epitope may play a role in the physiological function and pathophysiology of human DRG neurons.