On the basis of 16S rRNA gene sequence analysis and several key phenotypic features, it was ascertained that the culture cited as the type strain of the species Hyphomonas rosenbergii , ATCC 43869T, does not conform to the description of the species, [Weiner, R. M., Melick, M., O’Neill, K. & Quintero, E. (2000). Int J Syst Evol Microbiol 50, 459–469]. The type strain does not exist in any other established culture collection or with the authors who described this species. Therefore, it cannot be included in any scientific study. It is proposed that the Judicial Commission place the name Hyphomonas rosenbergii on the list of rejected names if a suitable replacement type strain is not found or a neotype is not proposed within two years following the publication of this Request for an Opinion.