Synanthropic filth flies are naturally evolved to live in close proximity to human and animal habitations, more than any other group of insects; they have a major negative economic impact, and significant veterinary and medical implications on people and animals. Although the high importance of synanthropic flies, yet, the information concerning species diversity, prevalence and seasonal abundance of these flies in Assiut Governorate is deficient. Therefore, the current study's objectives were to identify various species of synanthropic filth flies in the selected animal rearing stations and over the course of one-year duration, as well as to ascertain how seasonal variation affected the abundance of these flies in selected study sites in the Assiut Governorate, Upper Egypt. A total of 12749 flies were collected from three animal rearing stations in Assiut Governorate, from July 2020 to June 2021. The collected fly species were classified according to standard taxonomic keys. They belonged to seven dipteran families; Muscidae, Sphaeroceridae, Fannidae, Ulidiidae, Sepsidae, Calliphoridae and Sarcophagidae. Family Muscidae was the most prevalent family in all the studied stations (62.58%) while the least abundant families were family Calliphoridae (0.055%) and family Sarcophagidae (0.02%). There were statistically significant differences in numbers of collected flies in relation to seasonal variations (P. value <0.05). Summer and spring witnessed the highest incidence rates of flies followed by autumn, meanwhile the winter showed the least flies' abundance. For the assessment of the risk of vector-borne diseases, it is essential to know the prevalence of fly species. Thus these results are helpful for determining the suitable time of fly control programs in animal-production sites.