A 66-year-old woman developed bilateral facial paralysis as well as sensory and motor disturbances of extremities. Two months after the onset of paralysis, she also developed sensory disturbance of her trunk and vesicorectal disturbance, and her symptoms worsened gradually. Because the interferon-γ level in the cerebrospinal fluid was elevated, we suspected that her symptoms were caused by polyneuropathy and myelitis associated with infection. Her serum IgM and IgG antibodies against Borrelia garinii and B. afzelli were positive. Therefore, we diagnosed her as having neuroborreliosis. Her symptoms gradually improved after the combined administration of antibiotics and steroids. The present case report showed that it might be better to consider the possibility of neuroborreliosis when there are increasing concentrations of cytokine and chemokine, and that combination treatment with antibiotics and steroids can be used for the treatment of this disease.