We report a 64-year-old Japanese man with oculo-neuroborreliosis. His clinical features consisted of polyarthralgia, keratoconjunctivitis, chorioretinitis, optic neuritis, confusion, and polyradiculitis. Assay of antibodies to Borrelia species detected IgG-antibody to B. garinii in both serum and CSF. Progressive declining of serum IgG antibody titer against Borrelia garinii, in parallel with clinical improvement, was observed after administration of ceftriaxone.