Subterranean environments, even though they do not possess a primary production (photosynthesis), may present high biodiversity, faunistic originality, endemism, phylogenetic isolations and unique ecological and/or evolution events, in addition to rare taxa. Studies investigating the biological diversity in Neotropical caves are relatively rare and recent, and most of them have been conducted in Brazil. We sampled caves from the state of Bahia, northeastern Brazil, and through sampling sufficiency tests and richness estimators, we demonstrate that the normatization for the Brazilian cave laws is not adequate for its conservation and that only α diversity index is not enough to verify faunistic patterns. We suggest that a phylogenetic diversity index be more robust and accurate for conservation purposes, particularly the Taxonomic Distinctness index. Moreover, we propose that the sandstone complex caves from Chapada Diamantina National Park need to be classified as being of high subterranean biodiversity in a global scope.