Bats provide crucial ecosystem services like pest control and pollination and depend heavily on roost quality for their survival. Bats favor caves for the establishment of large populations thanks to favorable microclimatic conditions. Colombia has an important cave system in the Santander region that has not been fully explored, thus its importance for bat conservation remains largely unknown. Here we report the most updated list of the species present in the Macaregua Cave (Santander, Colombia) and comment on its use by different species. We found eight species that use the cave permanently or sporadically in addition to two previously known species. We also found a high population that ranges between 7,000–10,000 individuals. Macaregua Cave can now be recognized as the most bat-diverse (S = 10) cave in Colombia, harboring an important bat population of pest controllers and seed dispersers.