The 24th ICAR meeting was held in Sofia, Bulgaria, 8-11 May 2011. This report summarizes the presentations by the ICAR award winners, Earl Kern and Brian Gowen; the keynote address by Albert (ADME) Osterhaus; the Plenary lectures by Raina Fichorova, Ralf Bartenschlager and Esteban Domingo; the invited speakers for the symposia; and a few of those by contributors. This report aims to reflect the diversity of topics across different disciplines (chemistry to biology) discussed at ICAR: old viruses (smallpox), emerging viruses (SARS, new strains of influenza and flaviviruses), problematic viruses (HIV and HCV), sporadic viruses (arenaviruses), neglected viruses (enteroviruses), new research targets (for HCV) and new approaches (lethal mutagenesis). There were timely reports on promising compounds against adenoviruses, cytomegalovirus, HCV and HIV in clinical trials.This conference illuminated the constantly evolving field of antiviral chemotherapy by providing a forum to present and discuss new antiviral compounds, new uses for old compounds and exciting clinical results. This ICAR was a fitting testament to the 'father of antiviral chemotherapy', Bill Prusoff, who died aged 90 in April 2011.