Although there are various treatments for postherpetic neuralgia (PHN), none produces definitive effects. We report a case of 72-year-old woman who developed intractable PHN of the chest in which treatment with endoscopic transthoracic sympathicotomy (ETS) produced long-term effective results. When hyperesthesia of the sympathetic nerve participates in PHN, the blocking of sympathetic excitation seems to be effective for PHN suppression. The method using a single resectoscope is safe, accurate, yields excellent results cosmetically, and generates minimal invasion and very little postoperative pain. Although ETS is not always effective for all cases of PHN, it could be a useful method of treating patients with PHN that is resistant to conventional therapies.