This report is a case of 62-year-old man with anterior chest pain and pin pricking pain with allodynia affecting left T5 sensory dermatome for 3 months without history of vesicular skin eruption. He had a history of diabetes mellitus for 10 years and insulin therapy for recent 1 year. EKG, chest PA and rib series were normal. Serologic evaluation of IgG antibody to varicella-zoster virus was positive and was diagnosed as post herpetic neuralgia after zoster sine herpete. He was treated with left T5 nerve root block followed by thoracic epidural blockade and intercostal nerve block for 2 weeks. His VAS score decreased from 10 to 2 after 2 weeks of treatment. After 3 months, he revisited our clinic complaining right side chest pain followed by vesicular skin eruption 8 days after the onset of pain. He was treated as herpes zoster and tolerates well after 4 months.