We described herein Zhangixalus yunnanensis sp. nov., a new treefrog species from central and western Yunnan, China, which had previously been confused with Z. nigropunctatus, based on morphological and molecular evidence. Our phylogenetic analyses revealed that the new species is sister to the clade of Z. nigropunctatus and Z. melanoleucus with strong support (100% and 73% for BI and ML, respectively). Our morphological analysis suggested that Z. yunnanensis sp. nov. is distinctly different from all known congeners by the combination of the following morphological characters: black blotches on body flank and hind-limb, medium body size (SVL31.3–36.0 mm in males and 47.6–48.6 mm in females), head wider than long, iris yellowish-brown, dorsum uniformly green, vocal sac external, throat black, webbing greyish and fingers webbed one third and toes webbed half. Additionally, we revealed that the specimens ROM 38011 (Sa Pa, Vietnam) and VNMN 4099 (Son La, Vietnam) are neither Z. dorsoviridis nor Z. nigropunctatus, but probably represent one or two cryptic species of Zhangixalus pending further morphological and molecular data. Including the new species described herein, the genus Zhangixalus currently comprises 42 species, 30 of which are distributed in China with 11 species known from Yunnan. Amongst different zoogeographic regions in Yunnan, south-eastern Yunnan has the highest diversity of Zhangixalus, followed by western Yunnan and southern Yunnan. More studies are required to clarify the species diversity of this genus based on multiple lines of evidence (e.g. morphological and molecular data).