The taxonomic positions of four strains isolated from the mangrove rhizosphere were studied by a polyphasic approach using phenotypic, chemotaxonomic and genetic methods. The four isolates contain 2,4-diaminobutyric acid in their peptidoglycan, and rhamnose as the major cell wall sugar. The predominant menaquinones are MK-12 and MK-11. The predominant cellular fatty acids are iso-C16:0, anteiso-C15:0 and/or anteiso-C17:0. The G+C content of the DNA ranges from 70.0 to 73.3 mol%. The four strains formed a coherent cluster with Agromyces species in a phylogenetic inference based on 16S rDNA sequences. Interestingly, the four isolates grew well in the presence of 5% NaCl. The differences in some phenotypic and chemotaxonomic characteristics, 16S rDNA sequence similarity data and DNA-DNA relatedness data indicate that the four isolates represent three new species in the genus Agromyces, for which are proposed the names Agromyces luteolus for strain 8T (IFO 16235T = VKM Ac-2085T), Agromyces bracchium for strain 65T (IFO 16238T = VKM Ac-2088T) and Agromyces rhizospherae for strains 14T (IFO 16236T = VKM Ac-2086T) and 58(5) (IFO 16237 = VKM Ac-2087).