The paper provides morphological data of three turtle species: Black-breasted Leaf Turtle Geoemyda spengleri (Gmélin, 1789), Impressed Turtle Manouria impressa (Günther, 1882), and Big-headed Turtle Platysternon megacephalum Gray, 1831, which were recorded for the first time in Pu Luong Nature Reserve, Thanh Hoa Province. This study also biodiversity updates and increases the total number of known turtle species here to six, five of which are listed in the Vietnam Red List (2024), four species listed in the Vietnam Government Decree No. 84 (2021), and five species listed in CITES appendices and all six species are included in the IUCN Red List (2025).