AbstractITS, rps4, and atpB-rbcL sequences were used to test recent taxonomic rearrangements in the moss genus Brachytheciastrum. A starting phylogenetic hypothesis of Brachytheciaceae was used to subsample representative genera of each subfamily to obtain a robust backbone phylogeny and circumscribe Brachytheciastrum within the family. The strongly supported monophyletic Brachytheciastrum clade includes B. bellicum Vanderpoorten, Ignatov, Huttunen & Goffinet, comb. nov., B. collinum, B. dieckei, B. falcatulum, B. fendleri Vanderpoorten, Ignatov, Huttunen & Goffinet, comb. nov., B. leibergii, B. olympicum Vanderpoorten, Ignatov, Huttunen & Goffinet, comb. nov., B. trachypodium, and B. velutinum. No morphological synapomorphy was found for Brachytheciastrum due to the high uncertainty associated with the reconstruction of character states at the ancestor node of the genus. The revised circumscription of Brachytheciastrum has several consequences for the taxonomy of Brachytheciaceae. New infrafamilial rearrangements and combinations are discussed.