We determined almost complete 16S rRNA gene sequences of two Microbispora bispora (Lechevalier 1965) strains, ATCC 19993T (T = type strain) and JCM 3082. The two sequences were 99% similar to each other but exhibited only 81 to 87.8% similarity with the 16S rRNA gene sequences of seven other Microbispora strains. A phylogenetic analysis revealed that the two sequences clustered not only distantly from other Microbispora strains, but also outside the cluster containing members of the family Streptosporangiaceae. On the basis of the results of our phylogenetic analysis and the results of a comprehensive review of the genus Microbispora by Miyadoh et al. (S. Miyadoh, S. Amano, H. Tohyama, and T. Shomura, J. Gen. Microbiol. 136:1905-1913, 1990) in which chemotaxonomic and DNA-DNA hybridization analyses were performed, we propose that Microbispora bispora should be transferred to a new genus, Thermobispora gen. nov., as Thermobispora bispora comb. nov.