A new species was detected while conducting a monographic study of Cohniella Pfitzer (Orchidaceae, Cymbideae, Oncidiinae). Cohniella croizatii Cetzal & Carnevali is newly described from material collected in the vicinity of Puerto Ayacucho and from the upper Orinoco, Amazonas State, Venezuela. The new species is illustrated and its affinities are discussed. The novelty is similar to C. cebolleta (Jacq.) Christenson from northern Venezuela and Colombia, but differs in the callus that consists of three large, apical teeth of more or less similar size that emerge directly from the labellum disk, with the two lateral teeth marginally serrate to dentate on the proximal half. In contrast, the callus in C. cebolleta is more complex, consisting of five teeth that emerge from a conspicuous central platform, and the central tooth is proportionately larger.