Rift Valley fever virus (RVFV) is a serious emerging pathogen affecting human and livestock in sub-Saharan Africa, Egypt, Yemen, and Saudi Arabia, Since the first description of an outbreak in Kenya 1931. Inactivated tissue culture adapted Rift valley fever (RVF) virus vaccines were prepared using poly (lactic-co-glycolic acid) PLGA in different ratio and aluminum hydroxide gel as adjuvants. The prepared vaccines were sterile and safe induced no systemic or local clinical signs in sheep. The comparative evaluation of prepared vaccines in vaccinated sheep after a single dose showed that PLGA prepared vaccines stimulated the cellular and humeral immune response as compared with aluminium hydroxide gel vaccine. Application of such vaccines will add value to improve the locally produced RVF vaccine, as poly (lactic-co-glycolic acid) 50:50 induced early immuno-response, poly (lactic-co-glycolic acid) 85:15 induce prolonged immuno-response and the mixture of poly (lactic-co-glycolic acid) 50:50, 85:15 in a ratio (1:1) induce early and prolonged immuno-response.