Rift Valley Fever (RVF) is an acute, mosquito-b orne viral disease that has a significant global threat to humans and livestock. The seroprevalence and economic impact of RVF among small ruminants in some localities in Egypt were studied. The antibodies against RVF were detected using three serological tests ELISA, AGPT and SN T. The obtained results showed high incidence of RVF in sheep and in El-Sharkia an d Marsa Matrouh than in goat and in El-Dakhalia and El-Kaliobia governorates. Moreover, the SN T and ELISA showed higher sensitivity than AGPT. The SNT was sensitive and save the money in comparison with other test but less specific. Therefore, ELISA is most sensitive and economic test for detection of RVF among small ruminant.