The present work aimed to develop a new inactivated RVF vaccine Formulation adjuvanted by Peppermint oil (PMO) with Aluminum hydroxide gel (Alum gel) or without Alum gel, then ensure the safety and sterility of these vaccines and compare between them with the local RVF vaccine with Alum gel alone in sheep. This peppermint formulation including Alum gel adjuvant was the best of choice as it induced higher immunological enhancement. In addition, synergistic action was discovered in RVF inactivated PMO vaccine including Alum gel as the immune response detected by serum neutralization test (SNT). This vaccinated group of sheep was the highest while the group of sheep vaccinated with RVF vaccine adjuvanted with Alum gel only show the least antibody titer. The group of sheep, which was vaccinated with RVF, inactivated PMO without gel vaccine show intermediate level of antibodies. Moreover, the values of ED50 of the developed vaccines as well as the Alum vaccine alone were not exceed 0.02 which lies within the permissible level.