Within the framework of the project “Conservation of the Cave Fauna of Greece”, the Hellenic Institute of Speleological Research developed the Cave Fauna of Greece (CFG) Database (https://database.inspee.gr/, Fig. 1), a free online data infrastructure that provides reliable information on the taxonomy, distribution, conservation status and referenced literature for all cavernicolous animal species in Greece. Furthermore, it provides information on geography, protection status and the fauna of each cave, as well as the referenced literature. The database was compiled after gathering, critically evaluating and integrating all taxonomic and faunistic information for species recorded in the caves of Greece. It includes all species recorded up to date and currently regarded as valid. The taxonomic reference system is harmonized with the Pan-European Species directories Infrastructure (PESI, EU-nomen). Considerable effort was also made to find the locations of the caves and to solve problems of synonymies, misspellings, etc. CFG database is a comprehensive, dynamic and digitally-available reference for several user-groups: research scientists, policy and decision-makers, nature conservation community, the education community, and citizen scientists. It was developed and launched to serve as a basic tool for research and conservation policies of cave species and caves in Greece. Currently, it hosts 2,567 records of 843 valid species in 465 caves, 763 literature references for species and more than 440 cave descriptions references. The user can navigate through 3 themes: fauna, caves, and references. A species can be found either by searching the name (or part of it) or by browsing through the taxonomic hierarchy to look for names of organisms within a group. A cave can be found either by searching the name/synonym (or part of it) or by browsing through the administrative hierarchy. Navigation from species to caves and vice versa can be performed through the names of species and caves.