The genus Capoetais considered being a complex taxa of Iranian freshwater fishes in terms of taxonomy. Among the members of this genus, comparing morphometrics and meristic characteristics of Tuini fish (Capoeta damascina) from different basins do not allow their distinction despite some differences. Hence, osteological features can be considered as an important characteristic to investigate their taxonomy. In addition, knowledge of osteological features, particularly cephalic structures, can be use in understanding their biological features, such as feeding and respiration. Therefore, this study was aimed to describe osteological characteristics of Tuini fish from Tigris basin. To do so, 20 specimens were collected from the Gheshlagh River using electro fishing. Specimens were fixed into 10 percent buffered formalin after anaesthetizing and then cleared and stained for osteological examinations. The skeletal structure of this species showed differences in form of some bony elements including jaws, quadrate, symplectic, parasphenoid, various parts of occipital region and urohyal in comparison with other cyprinids which can be considered as discernible osteological characters of this species. Regarding the weakness of morphometric and meristic traits for taxonomic study of the member of C. damascina, the findings of this research can be set as the basis for future taxonomic studies of this taxon.