Machupicchu Historical Sanctuary is a natural protected area that bears a considerable orchid diversity. Masdevallia is one of the most common, showiest, and distinctive genera among Machupicchu orchids, where six species are currently known. Here, we describe a new species of Masdevallia from Machupicchu, which we name Masdevallia bastantei. The species is similar to M. karineae but differs in the long flowers of 12 to 17 cm in length and a campanulate, incanous, maculate sepaline tube. We provide a description and illustrations of this new species. Furthermore, we present pictures and a key including all Masdevallia species that occur within the Machupicchu Historical Sanctuary.