Enteroviruses, members of the family Picornaviridae (more than 70 serotypes), are distributed throughout the world and cause a broad spectrum of clinical manifestations in man and animals. Human enteroviruses are classified into 5 species: human enteroviruses A to D, and Poliovirus. Recombination has long been known to be an important property of poliovirus genetics; however, recombination has been recently shown to be also ubiquitous in non-polio enteroviruses. Prototype enterovirus strains have complex phylogenetic relations and all currently available enterovirus strains are recombinant to prototype strains. The extremely high rate of recombination allows the fragments of the enterovirus genome to evolve independently at a microevolutionary scale. Recombination strictly takes place between the members of the same species, usually outside the capsid-encoding genome region. Therefore, it can be concluded that the species enterovirus exists as a worldwide reservoir of the genetic information that shuffles frequently to produce new virus variants. This new model of the genetics of enterovirus accounts for failures to associate the serotype of enteroviruses and the form of the disease caused. The contents of this review have been published in the Reviews in Medical Virology, 2005.