Farm animals have a high economic importance because of their important products such as meat, milk, hair as well as skin, not only in our country but also all over the world. These animals can be infected by serious pathogens, external and   internal parasites causing severe damage, which result in losses of animal production. Accordingly, the study of external parasites with light microscope and scanning electron microscope were recorded, to clarify the exact composition of species. Also, differences in the morphological characteristics between the two Myiasis species: Oestrus ovis (Linnaeus, 1758)and Cephalopina titillator (Clark 1797), were investigated.