Herpes zoster as a result of reactivated varicella-zoster virus is characterized by vesicular eruptions on skin and painful neuralgia in the dermatome distribution. Pain during an acute phase of herpes zoster has been associated with a higher risk of developing postherpetic neuralgia. The current therapies for herpes zoster including analgesics and sympathetic nerve block as well as antiviral agents are important to alleviate pain and prevent postherpetic neuralgia. However, in some cases, the pain does not respond well to these treatments. We had a case in which a patient with herpes zoster did not respond to conventional therapy so we attempted to administer intravenous infusion of vitamin C which resulted in an immediate reduction in the pain.