We analyzed the role of taboos for the protection of species listed as “threatened” by the World Conservation Union (IUCN), and also for species known to be endemic and keystone. The study was limited to taboos that totally avoid or prohibit any use of particular species and their populations. We call them specific–species taboos. Through a literature review, 70 currently existing examples of specific–species taboos were identified and analyzed. The species avoided were grouped into biological classes. Threat categories were determined for each species, based on the IUCN Red Data Book. We found that ~ 30% of the identified taboos prohibit any use of species listed as threatened by IUCN. Of the specific–species taboos, 60% are set on reptiles and mammals. In these two classes, ~ 50% of the species are threatened, representing all of the threatened species in our analysis, with the exception of one bird species. Both endemic and keystone species that are important for ecosystem functions are avoided by specific–species taboos. Specific–species taboos have important ecological ramifications for the protection of threatened and ecologically important populations of species. We do not suggest that specific–species taboos are placed on species because they are, or have been, endangered; instead, we emphasize that species are avoided for a variety of other reasons. It is urgent to identify and analyze resource practices and social mechanisms of traditional societies, such as taboos, and to investigate their possible ecological significance. Although it may provide insights of value for conservation, not only of species, but also of ecosystem processes and functions, such information is being lost rapidly.