Oritrophium (Kunth) Cuatrec. is a neotropical genus with a disjunct distribution in the Andes (Bolivia, Colombia, Ecuador, Peru, and Venezuela), the center of Mexico, and the mountains of the Guiana Shield in Venezuela, with a remarkable diversity in Ecuador. We present a taxonomic study for Ecuador that represents the first modern and exhaustive revision of this genus in this country. We recognize eight species and four subespecies. We provide a dichotomous key, descriptions, synonyms, morphological and nomenclatural notes, distribution maps, and photographs of living plants. Three names are lectotypified and two names are neotypified.