Bulbophyllum kubahense is closely related to B. refractilingue. B. kubahense appears to have flowers with segments more rounded, obtuse at the apices, where B. refractilingue appears to have flowers more pointed on the apices when compared to the photos. Also, based on flower size, with B. kubahense measuring 2.5 cm vs. less than two for B. refractilingue, this flower matches B. kubahense measuring 2.8/2.6 cm. Dr. J.J. Vermuelen, the "Orchids of Borneo Vol 2" describes B. refractilingue as having well defined teeth along the lower margins of the column; however, there is no evidence of these in this plant which appears to have a smooth margin. Both species have very well defined downswept thick horns like this plant.