The names of all plant pathogenic bacteria which have been effectively and validly published in terms of the international. Code of Nomenclature of Bacteria and the Standards for Naming Pathovars are listed to provide an authoritative register of names for use by authors, journal editors and others who require access to currently correct nomenclature. Included are species, subspecies and pathovar names and details of type and pathotype strains reported from 1980 to 2007. An explanation of how to use this list is provided. In recent years the taxonomy of plant pathogenic bacteria has been extensively revised. For some taxa there are several valid synonyms. Unless otherwise stated, the most recently published name is used in this list as the reference name (in bold italic) to which all other synonyms are referred. This does not mean that the reference name is always to be preferred. A synonym, i.e., a previously published name for the same organism, may represent a classification considered by individual scientists or groups to give a more coherent taxonomy and may be used. This list is presented by the International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria, Carolee T. Bull Convener.