A taxonomic study of the Colombian species of the genus Muhlenbergia is given. The aspects related to the classification, nomenclature, and morphological variation are discussed. The genus Muhlenbergia is represented in Colombia by 14 species. The following new combinations and new names are made: Muhlenbergia bryophilus (Doll) P. M. Peterson, Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P. M. Peterson, Muhlenbergia pereilema P. M. Peterson, and Muhlenbergia phalaroides (Kunth) P. M Peterson. Muhlenbergia cleefii Laegaard is reduced as synonym of Muhlenbergia fastigiata (J. Presl) Henrard. Muhlenbergia beyrichiana Kunth, Muhlenbergia ciliata (Kunth) Trin., Muhlenbergia erectifolia Swallen [= Ortachne erectifolia (Swallen) Clayton], Muhlenbergia nigra Hitchc., and Muhlenbergia wallisii Mez [= Agrostopoa wallisii (Mez) P. M. Peterson, Soreng & Davidse] are excluded from this study. Keys to recognize the species that inhabit Colombia are given, as well as description of the species, synonyms, geographical distribution, morphological and ecological observations, uses, and chromosome numbers.