Viruses pose a unique problem from the perspective of innate immunity in that they are biochemically similar to the host. This similarity has forced the evolution of specialised immune recognition mechanisms for detecting virus infection and of unique mechanisms for restricting virus replication. As such, innate immunity to viruses overlaps with that utilised for defence against other organisms but also displays key differences that are often overlooked in more general meetings on innate immunity. The Keystone Symposium on Innate Immunity to Viral Infections will highlight the similarities and difference in antiviral defence across vertebrate and non-vertebrate species. It aims to bring together specialists in virology, immunology and pathogenesis to discuss the mechanisms involved in virus/host discrimination, the effector responses involved in restricting virus spread and the impact of innate antiviral immunity on disease. The Symposium will create the first forum for exchange of ideas between virologists, immunologists and clinicians, offering a unique opportunity for these disparate research communities to come together and look at antiviral immunity from the perspective of contemporary medicine and biology. Importantly, this meeting will take place concurrently with the symposium on Pathogenesis of Respiratory Viruses. Joint plenary sessions and synergistic interactions between both meetings will further contribute to the development of an integrated view of viral disease, immunity and pathogenesis.