The Sixth Report of the International Committee on Taxonomy of Viruses (ICTV) presents the latest classification and nomenclature of viruses. This report, compiled by over 400 virologists, includes the proceedings of the ICTV since 1990, decisions from mid-term meetings in 1991 and 1992, and the Ninth International Congress of Virology in 1993. The report reflects the ongoing development of the universal system of virus taxonomy, which has been based on international consensus and pragmatism since 1966. The system aims to provide a single, unified classification for all viruses, which is essential for understanding their biology, evolution, and pathogenicity. The report includes detailed descriptions of virus taxa, their structural and genomic properties, and their classification based on host, nucleic acid type, and other characteristics. It also provides a glossary of abbreviations and virological terms, virus diagrams, and indexes for authors, viruses, and taxonomic groups. The report acknowledges the contributions of the Mayne Bequest Fund and the University of Queensland, as well as the efforts of the ICTV's Study Groups, Subcommittees, and Executive Committee. The report emphasizes the dynamic nature of virus taxonomy, which must continue to evolve as new viruses are discovered and characterized. The ICTV's work is essential for the advancement of virology and the development of diagnostic and therapeutic strategies against viral diseases.The Sixth Report of the International Committee on Taxonomy of Viruses (ICTV) presents the latest classification and nomenclature of viruses. This report, compiled by over 400 virologists, includes the proceedings of the ICTV since 1990, decisions from mid-term meetings in 1991 and 1992, and the Ninth International Congress of Virology in 1993. The report reflects the ongoing development of the universal system of virus taxonomy, which has been based on international consensus and pragmatism since 1966. The system aims to provide a single, unified classification for all viruses, which is essential for understanding their biology, evolution, and pathogenicity. The report includes detailed descriptions of virus taxa, their structural and genomic properties, and their classification based on host, nucleic acid type, and other characteristics. It also provides a glossary of abbreviations and virological terms, virus diagrams, and indexes for authors, viruses, and taxonomic groups. The report acknowledges the contributions of the Mayne Bequest Fund and the University of Queensland, as well as the efforts of the ICTV's Study Groups, Subcommittees, and Executive Committee. The report emphasizes the dynamic nature of virus taxonomy, which must continue to evolve as new viruses are discovered and characterized. The ICTV's work is essential for the advancement of virology and the development of diagnostic and therapeutic strategies against viral diseases.