An integrative taxonomic analysis was used to delimit and diagnose a new species of the Cyrtodactylus brevipalmatus group from Tak Province in western Thailand. Although Bayesian phylogenetic analyses place C. denticulatus sp. nov. within the brevipalmatus group, the new species is neither nested within nor is it the sister species of any other species in the brevipalmatus group. Furthermore, based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs, it bears an uncorrected pairwise sequence divergence of 7.87–21.94% from all other species in the brevipalmatus group. Cyrtodactylus denticulatus sp. nov. is differetiated from all other species in the brevipalmatus group by having a number of unique charateristics such as denticulate ventrolateral body folds and ventrolateral subcaudal ridges, characters not seen in any other species of the group (n = 51 individuals). Additionally, based on a multiple factor anlaysis, C. denticulatus sp. nov. does not overlap with any other species in multivariate space. The discovery of C. denticulatus sp. nov. underscores the unrealized diversity of upland ecosystems across Thailand and the urgent need for increased exploration and conservation of these unique imperiled montane refugia, especially in this era of climate change.