Mammalian reovirus had been the major focus for molecular understanding of the Reoviridae and has served as a model system for the other members of the family. Indeed, most of our initial understanding of molecular biology and processes involved in virus replication and pathogenesis for the members of the family was generated from reovirus studies. With this platform two other members of the family causing disease in human and/or animals have gained in prominence and the molecular interactions from a structural level through to host-virus interactions as well as the function of the structural and non-structural proteins in the virus life cycle has been investigated in detail.This book reviews our current understanding of Reoviridae entry, disassembly/assembly and egress in addition to updating high resolution structures of virus proteins and capsids from three different genera of the family.