A taxonomic revision of Cnemaspis siamensis (Smith 1925) revealed it to be a complex composed of four species: C. siamensis (Smith 1925) which occurs on Ko Tao Island, Surat Thani Province and on the peninsula ranges from Khao Mod, Surat Thani Province in the south, northward east of the Tenasserim Mountains to Kaeng Krachan National Park, Phetchaburi Province; C. chanardi sp. nov. ranging from Tai Rom Yen National Park, Surat Thani Province in the north, southward through the western foothills of the Nakhon Si Thammarat and Sankalakhiri Mountains to Phuphaphet Cave, Satun Province and westward to Khlong Thom District, Krabi Province; C. vandeventeri sp. nov. ranging from Kapur District, Ranong Province southward to at least Khlong Had Sompen, District, Ranong Province west of the Tenasserim and Phuket Mountains and possibly all the way to Phuket Island; and C. kamolnorranathi sp. nov. restricted to the northwestern section of the Itshmus of Kra, ranging from Tham Khao Sonk, Thachana District, Surat Thani Province southward to Tai Rom Yen National Park, Surat Thani Province. These species are easily separated from one another on the basis of their unique combination of having or lacking precloacal pores, dark gular markings, a series of lightly colored bars on the flanks, and a lightly colored, prescapular crescent as well as other aspects of squamation. Four additional new species from western and southern Thailand are also described: C. huaseesom sp. nov. from Sai Yok National Park, Kanchanaburi Province; C. punctatonuchalis sp. nov. from Thap Sakae District, Prachuap Khiri Khan Province; C. narathiwatensis sp. nov. ranging from Waeng District, Narathiwat Province south to Bang Lang, Yala Province; and C. niyomwanae sp. nov. from Thum Khao Ting, Palean District, Trang Province, Thailand. These species are differentiated from each other and all other Cnemaspis on the basis of their unique combinations of color pattern and squamation characters. This brings the total number of species of Cnemaspis in Thailand from five to 12 and continues to illustrate that the unrealized diversity in this group is a function of unfocused collecting efforts coupled with poor taxonomy.

We describe a new sylvicolous Cyrtodactylus Gray from Phuket Island, southwestern peninsular Thailand, having a band-ed pattern, precloacal groove, continuous series of enlarged pore-bearing femoro-precloacal scales, and strongly devel-oped tuberculation—characters that distinguish it from all congeneric taxa except C. macrotuberculatus Grismer &Ahmad, 2008 from Peninsular Malaysia, from which it can be separated mainly by having three instead of four dark bands between the limb insertions and a precloacal groove in females.

We describe a new lowland forest-dwelling species of the genus Acanthosaura from Phuket Island and the Phuket mountain range in southwestern Thailand. Acanthosaura phuketensis sp. nov., the 11^th species in the genus, seems most closely related to A. crucigera from Myanmar and western Thailand and A. cardamomensis from the Cardamom Mountains, but can be differentiated from them by a combination of morphological and coloration characteristics. This new discovery stresses the importance of preserving the last forest patches remaining on Phuket Island, home to three other squamate endemics.

We describe Oligodon saiyok sp. nov. from Benjarat Nakhon Cave Temple, Sai Yok District, Kanchanaburi Province, western Thailand. It is characterized by a maximal known SVL of 626.1 mm; 13 maxillary teeth, the posterior two enlarged; 8 supralabials; 17-17-15 dorsal scale rows; 181–187 ventrals and 38–43 subcaudals; a single anal; hemipenes extending in situ to the 18th subcaudal; dorsum with 21–22 dark blotches or white rings without vertebral or lateral stripes; and venter with a dense network of subrectangular dark blotches. It is the 7th squamate species believed to be endemic to Sai Yok District.

A new cave-dwelling species of Cyrtodactylus is described from Chiang Mai Province in northern Thailand. Cyrtodactylus dumnuii sp. nov. may be distinguished from all other congeners by the possession of a series of enlarged femoral scales, disjunct precloacal and femoral pores in males (minute precloacal pores variably present in females), a relatively high number (18–22) of closely spaced, regularly arranged dorsal tubercle rows, well-defined non-denticulate ventrolateral folds, transversely enlarged subcaudal plates, and a color pattern of approximately six pairs of alternating light and dark transverse bands on the trunk. It is the nineteenth member of the genus recorded from Thailand and the eighth Thai Cyrtodactylus known to be a facultative troglophile.