We conducted a taxonomic review of the genus Microbispora using chemotaxonomic and DNA-DNA hybridization techniques, and reached the following conclusions: Microbispora viridis should be transferred to the genus Actinomadura as Actinomadura rugatobispora comb. nov., nom. nov. (type strain SF2240 = IFO 14382 = JCM 3366) and Microbispora echinospora should be transferred to the genus Actinomadura as Actinomadura echinospora comb. nov. (type strain JCM 3148 = ATCC 27300). We also propose that Microbispora rosea, Microbispora amethystogenes, Microbispora chromogenes, Microbispora diastatica, Microbispora indica, Microbispora karnatakensis and Microbispora parva should be combined into the species Microbispora rosea subsp. rosea (type strain JCM 3006 = ATCC 12950), and that Microbispora aerata, Microbispora thermodiastatica and Microbispora thermorosea should be combined and transferred to the new subspecies Microbispora rosea subsp. aerata comb. nov. (type strain IFO 12581 = ATCC 15448). Microbispora bispora clearly differs from these ten strains at the species level