A 65-year-old Japanese woman developed vesicular eruptions on her right ear due to varicella zoster virus (VZV) reactivation, followed by cranial polyneuritis and meningitis affecting her right cranial nerves V, VII, VIII, IX, and X. After acyclovir administration, her facial paralysis worsened. Intravenous methylprednisolone and vitamin C were administered on Day 4 post-admission. Her symptoms steadily improved, and by Day 45 she had fully recovered. Cranial polyneuritis is a rare complication of VZV reactivation, and there is no established method of treatment. This is the first report of full recovery from cranial polyneuritis using intravenous vitamin C as ancillary treatment.