Twenty Egyptian Balady sheep were divided into 4 groups each of 5 animals. The first group was vaccinated with Rift Valley fever cell culture live attenuated vaccine. The second group received Peste Des Petits Ruminants cell culture live attenuated vaccine. The third group was vaccinated with the two vaccines mixed together. The fourth group was kept as an un-vaccinated control group. All animals remained clinically normal throughout the experimental period. A decrease in the total leukocytic count could be detected only through the first week post vaccination. There was an increase in the total serum protein and in the albumin-globulin ratio, Kidney and liver functions were not affected. Cell-mediated immune response could be detected in the first few weeks post vaccination. Neutralizing antibodies to RVF and to PPR could be detected in the first and in the second group by the first and second week respectively. Peak titres could be detected by the 4th week in both groups, the third group acquired neutralizing antibodies to both viruses.