Abortions in sheep represent an important cause of the reduction of productivity and the increase economic losses. There are numerous potential reasons for abortion in ewes, yet making an authoritative finding is frequently difficult. This investigation, identified instances of abortion among sheep in various areas in El-Menoufia governorate. One hundred and ten serum samples were collected from 65 aborted sheep and 45 in contact one. The samples were analyzed to determine the suggested viral etiological determinants. The antibodies against of Bovine Viral Diarrhea Virus (BVDV), Bovine Herpes Virus (BHV), Rift Valley Fever Virus (RVFV) and Bluetongue Virus (BTV) were detected in the serum samples obtained from aborted sheep by serum neutralization test (SNT) and indirect enzyme linked immunosorbent assay (IELISA). The result of SNT showed positive percentage against BVD, BHV, RVF and BTV as 14.54%, 0.9%, 66.36% and 0.9% respectively. While the results of ELISA test was 18.18%, 3.63%, 77.27% and 2.72% for the four viruses respectively. The results of present study concluded that the RVF is the main viral cause for abortion in sheep in El-Menoufia governorate.