Originally initiated as a 1986 Keystone meeting, and later continued by Dr. Margo Brinton as primary organizer, for more than 25 years the triennial International Symposium on Positive Strand RNA Viruses has provided an international forum for recent research on human, animal, plant, insect, and bacterial viruses with positive-strand RNA genomes. These pathogens constitute the largest group of viral agents, including for example, Poliovirus, Dengue and West-Nile virus, SARS-coronavirus, Chikungunya virus, and human hepatitis viruses, such as HAV and HCV. The diseases these viruses cause are of major medical, veterinary, agricultural, and economic importance. In this meeting, now back under the roof of Keystone, basic research, the foundation of the fight against viral diseases, will be amalgamated with sessions focusing on immunological or pharmacological control of disease and new technological advances. This will create an outstanding forum for dissemination of the latest research advances among leading virologists worldwide, also creating possibilities for exciting and productive collaborations between academic and corporate scientists. Plenary sessions will be organized around themes highlighting the similarities between diverse virus systems and aim to increase discourse and interactions among researchers working on a wide variety of viruses. The different backgrounds of participants will require speakers to start with an overview of their research area before presenting their own recent data. The meeting’s traditional informal and stimulating environment will be an excellent experience for young investigators. The symposium is renowned for its large and highly interactive poster sessions, a prominent feature allowing all participants to present their work and receive feedback.