Herpes zoster myelitis (HZM) is one of serious complications of herpes zoster infection. Although HZM is recognized as a complication mainly occur in immunocompromised patients, HZM in immunocompetent patients have been reported increasingly. We reported two cases of HZM in immunocompetent patients. Based on favorable prognosis and no previous evidence of viral invasion in spinal cord, we suggest that the pathomechanism of HZM in immunocompetent patients is immune- mediated pathogenesis rather than direct invasion of zoster virus.