The descriptive osteology of Cyprinion milesi is hereby provided for the first time and compared with those of two other Iranian members of this genus, i.e. C. macrostomum and C. kais. For examine of osteological characteristics of this species, 12 collected specimens from Sarbaz River at Mokran basin, southeastern Iran were stained using Alizarin red S. The skeletal elements were separately photographed and described. Based on the results, differences in the osteological characters between C. milesi with C. macrostomum and C. kais include: the neurocranium in C. macrostomum and C. kais is sub triangular whereas in C. milesi is narrow and triangular, the lateral and posterior corners of supraethmoid in C. milesi unlike C. macrostomum and C. kais is elongated posteriorly connecting the lateral process of the parethmoid, the curvature of lower jaw in C. milesi is between the range of that of C. macrostomum and C. kais, the ceratohyal in C. milesi is two times longer than that of C. macrostomum and C. kais, the horizontal arm of the preopercle and the length of opercle in C. milesi are longer than that of C. macrostomum and C. kais, the number of dorsal fin pterygiophores in C. milesi is lower than those of C. macrostomum and C kais, the origination of dorsal fin in C. milesi is anterior than that of C. macrostomum, in C. milesi, the supraneurals are separated from each other whereas in C. macrostomum and C. kais, they are articulated with each other and the last unbranched dorsal fin ray in C. milesi is more slender in shape than that of C. macrostomum and C. kais and its serration is covering one-third of its length, the neural complex is T-shape in C. milesi but it is axe-shape in other studied Cyprinion.

Inland water Fishes of Iran, Osteology, Cyprinidae, Ichthyology, Biodiversity.