An integrative taxonomic analysis delimits and diagnoses the new species Hemiphyllodactylus cattien sp. nov. from Cat Tien National Park, Dong Nai Province, southern Vietnam-the eighth species of Hemiphyllodactylus to be described from Vietnam. The new species is recovered as the sister species to a clade comprised of H. indosobrinus from Laos and H. flaviventris from Thailand based on phylogenetic analyses using ND2 mtDNA gene sequences. Unlike the vast majority of Hemiphyllodactylus which are site-restricted upland endemics, Hemiphyllodactylus cattien sp. nov. is a lowland species collected from one of the most well-surveyed regions in Vietnam. Its discovery further emphasizes the need for continued re-sampling of survey sites already considered to be well-explored.