Brachial radiculoplexitis is characterized by acute onset of shoulder and arm pain followed by weakness and sensory loss. Brachial radiculoplexitis by herpes zoster is a rare disease, which can be diagnosed by careful history, electrodiagnosis and MRI. It has remained uncertain about clinical characteristics, treatment, and prognosis. Better understanding of this disease helps earlier diagnosis and prompt treatment to minimize neurologic sequale. We present two cases of subacute brachial radiculoplexitis preceded by herpes zoster infection.