We describe two adult cases of neurologic complications occurring after the administration of the influenza vaccine. The first case described is a 68 year-old man who experienced paresthesias of the upper and lower extremities two weeks after vaccination, and the second case was a 64 year-old female who exhibited paraplegia eighteen days after vaccination. Diagnosis of acute idiopathic demyelinating polyradiculopathy (Guillain-Barré syndrome) was made for both patients, and intravenous gammaglobulin therapy was given with marked improvement of the first case, but poor response on the second case. Although the efficacy of influenza vaccination has been widely accepted, such neurologic complications might occur in the elderly and adult population. Even if Guillain-Barré syndrome was a true side effect of vaccination, the risk is substantially lower than is the risk for complications following influenza. The rare occurrence of neurological complications after influenza vaccine should not discourage against the vaccination.