A soil isolate, strain F829T, which had provisionally been assigned to the genus Nocardia, was subjected to a polyphasic taxonomic study. An almost complete 16S rDNA sequence was determined for this strain; the sequence was aligned with available sequences for nocardiae and phylogenetic trees were inferred using three tree-making algorithms. The organism showed a combination of phenotypic properties typical of nocardiae and formed a distinct phyletic line within the evolutionary radiation of species of the genus Nocardia, being most closely related to Nocardia asteroides ATCC 19247T. Strain F829T was readily distinguished from representatives of species of Nocardia with validly published names on the basis of phenotypic data, notably from the type strain of N. asteroides. It is proposed that the organism be recognized as a novel species of Nocardia, Nocardia caishijiensis sp. nov. The type strain is F829T (=AS 4.1728T=JCM 11508T).