This work deals with the cellular and humeral immune response in sheep vaccinated with a trivalent inactivated oil Foot and Mouth Disease (FMD) vaccine produced locally in Egypt. Thirty sheep were vaccinated with the Egyptian FMD inactivated trivalent oil vaccine using a dose of 1.5 ml/animal inoculated subcutaneously while ten sheep were kept as control. Delta optical density of lymphocyte blastogenesis assay at day 0, 3, 7, 14, 21 and 28 days post vaccination (DPV) showed that there was a significant difference between vaccinated and control groups started at 3 DPV and increased gradually till 21 DPV. The phagocytic percentage started at 3 DPV and reached its highest (P<0.05) at 21 DPV. Regarding the phagocytic index, there was a significant difference (P<0.05) between vaccinated and control sheep groups starting at 3 DPV with its highest value at 21 DPV. At day 0, 3, 7, 14, 21 and 28 DPV an increase in the mean IL-6 and IL-12 concentration with a significant difference between the vaccinated group and the control group at 3 DPV and gradual increase (P<0.05) at 21 DPV was observed. In addition, serum neutralization and ELISA tests revealed that all vaccinated sheep exhibited detectable antibody levels against the three serotypes of FMDV from the first week post vaccination (WPV) and became protective at 3^rd WPV. We concluded from the results that immune response was improved by the Egyptian FMD vaccine.