Enterovirus A71 (EV-A71) belongs to the species group A in the Enterovirus genus within the Picornaviridae family. Although usually causes self-limiting hand, foot, and mouth disease or herpangina, it may also rarely cause severe neurological complications such as acute flaccid paralysis (AFP) or encephalomyelitis whose outcome is often fatal. Severe disease has been observed in young children during the large outbreaks that occurred in the Asia Pacific region in the two last decades. In this chapter, we describe the microbiological, epidemiological, clinical, and pathological features of EV-A71 and discuss the pathogenesis of the disease