Abstract Introduction: Postherpetic neuralgia (PHN) is a painful condition that occurs after herpes zoster skin lesions have subsided and that lasts for more than 1 month. PHN is usually difficult to treat. We herein present two cases of PHN comorbid with spinal metastasis of a malignant tumor. Both patients responded well to an epidural block. Case presentation: Patient 1 was a 54-year-old woman who had PHN for 35 days. Patient 2 was a 74-year-old woman who had PHN for 65 days. Both patients were treated with an epidural block and found to have spinal metastasis from a malignant tumor. Discussion: The routinely used dermatological medications for the treatment of herpes zoster and PHN have slow and unsatisfactory analgesic effects. Epidural block treatment provides a new approach for patients who cannot tolerate or do not respond to these commonly used drugs. Physicians should pay special attention to patients who have a history of a malignant tumor or are suspected to have spinal disease. Computed tomography or magnetic resonance imaging of the spine is recommended for such patients, and epidural block treatment should be performed after a spinal tumor or other lesions have been excluded. Conclusion: Epidural block treatment provides a new approach for patients of herpes zoster or PHN, but the treatment should be performed after a spinal tumor or other spinal lesions have been excluded.