A new endemic species, Cyrtodactylus thochuensis sp. nov. from Tho Chu Island in Kien Giang Biosphere Reserve off the southern coast of Vietnam, is differentiated from all other species of Cyrtodactylus by the following combination of characters: maximum SVL 86.3 mm (n=6); no precloacal groove; 3-5 precloacal pores arranged in an angular series; a series of enlarged femoral scales contacting a wide patch of enlarged precloacal scales; 3-6 intersuparanasals in contact with rostral; 20-26 strongly keeled, longitudinal rows of tubercles at midbody; and 30-40 transverse rows of ventral scales between the ventrolateral folds. This species most closely resembles C. condorensis Smith and C. paradoxus (Darevsky & Szczerbak).