Although the 2009 Swine flu (H1N1) pandemic has apparently been abolished, there are still lessons to be learnt. We reviewed the clinical and pathological manifestations of CNS involvement of influenza A virus infection. Neurologic disorders were most commonly seen as underlying medical conditions in swine flu, and neurological complications of the H1N1 vaccination. The major point with regard to the H1N1 pandemic is a mild disease with high contagiosity, which can have severe outcomes in those with underlying diseases including neurological ones.