Hydrobioid freshwater gastropods were collected from mainland and insular Greece. Several threatened taxa, such as Graecoanatolica vegorriticola, Pseudamnicola negropontina, Pseudamnicola pieperi, Pseudobithynia eubooensis and Pseudoislamia balcanica, were recorded from new localities. Trichonia trichonica, which has been considered extinct from its type locality for the last twenty eight years, was re-discovered, whereas the presence of Daphniola exigua, G. vegorriticola, Marstoniopsis graeca, P. pieperi and Pseudobithynia trichonis in their type localities was verified. The taxonomic status of P. negropontina and the newly discovered populations of G. vegorriticola was elucidated using COI sequence data. The new data recorded during this survey indicate that the IUCN status of some Greek endemic hydrobioids needs to be updated.