We report a 79-year-old woman with rheumatoid arthritis on prednisolone and methotrexate who developed herpes zoster followed by central nervous system dysfunctions and sepsis. The patient noticed pain in the left neck and upper limb. Herpes zoster developed on the painful area three days later. The patient was admitted to our hospital 7 days after occurrence of the pain. Acyclovir, 750 mg/day, was started. Sudden muscle weakness of the lower limbs developed on the next day following admission. Acyclovir was increased to 1000 mg/day and continued for 14 days. The patient's clinical course was complicated by pneumonia, pulmonary cryptococcosis, and sepsis. The general condition was improved by intensive care. A rehabilitation program was begun 13 days after admission. The muscle strength of the left upper limb and both lower limbs improved; however, the patient could not regain her usual activity of daily living. She was referred to another rehabilitation hospital.