The Gaoligong Mountains are characterized by large variations in elevation and topography, which support high levels of biodiversity and endemism that remain largely understudied. Herein, based on the integration of morphological comparisons and phylogenetic reconstruction, we describe a new species of Rhacophorus from the northern Gaoligong Mountains, Yunnan Province, China. The new species, Rhacophorus dulongensis sp. nov., is morphologically distinguishable from its congeners based on the differences in body size, head length, tibia length, snout and tongue shape, toe webbing formula and coloration, ventral skin texture and coloration, dorsal pattern and coloration, body macroglands, iris coloration, and pattern of markings on flanks. Phylogenetically, it differs from its congeners by uncorrected p-distances of >4.8% for the 16S rRNA gene fragment. Rhacophorus dulongensis sp. nov. is likely to be found in Myanmar, considering its type locality lies close to the China-Myanmar border. The phylogenetic analysis revealed that the “widespread” species, R. rhodopus, is a species complex and a composite of five distinct lineages. The results revealed that R. napoensis is also found in Vietnam, making it a new country record for Vietnam. Interestingly, R. dulongensis sp. nov. likely breeds in bamboo, a hidden behavioral characteristic that makes them easy to overlook. Given the ongoing habitat loss and degradation in the region, further biological exploration is urgently needed in the Gaoligong Mountains as a biodiversity reservoir.