Viruses are major human pathogens that cause a wide range of infectious diseases, representing a constantly recurring challenge to the health of individuals and the functioning of human society. Only a profound understanding of viral biology will provide the basis for developing and improving antiviral therapies. While RNA turnover has long been studied in the context of cellular gene regulation and quality control mechanisms, the interplay between RNA turnover and viral life cycles is only now emerging as a key component of virus-host interactions. For example, Herpes viruses, Poxvirus, Influenza virus and SARS-Coronavirus encode ribonucleases that cleave host mRNA and thereby support virus reproduction. Flaviviruses such as Dengue virus, West Nile virus and Hepatitis C virus encode a non-coding RNA that blocks Xrn1, a major cellular exoribonuclease, as a means to escape from an antiviral activity. The endonuclease RNase L is another component of the mammalian antiviral defense system, highlighting the importance of ribonucleases in the encounter of viruses with their host cells. This EMBO Workshop will bring together molecular biologists working on basic mechanisms controlling RNA turnover with virologists exploring RNA turnover in the context of virus-host interactions, and propel the scientific exchange in this emerging area of research.