A multiplex PCR technique for the rapid identification of Saccharomonospora strains was developed. Primers for the four validly described Saccharomonospora species were designed by aligning previously published 16S rRNA sequences. These primers were found to be species-specific through the application of a specificity test. Four species-specific primers were added to a single reaction tube together with a universal reverse primer corresponding to the 3' terminus of 16S rRNA genes. The representative strains of the four species could be differentiated by the PCR products characteristic of each species. The five strains of ''Saccharomonospora caesia'' yielded an identical PCR profile to that of Saccharomonospora azurea K161(T) as supposed from the same 16S rRNA sequence between S. azurea K161(T) and the strains of ''S. caesia''. The five strains of Saccharomonospora glauca and the five strains of Saccharomonospora viridis showed identical results to those of corresponding representative strains. It is now possible to rapidly identify the strains of the genus Saccharomonospora using this multiplex PCR assay. This method was found to be simple, reproducible and species-specific.