This study was performed on 9 adult sheep divided into 3 groups, one group included nonpregnant vaccinated sheep, second group was pregnant vaccinated ewes and the third group was nonpregnant non-vaccinated kept as control. Some of the vaccinated animals showed a slight elevation of body temperature. Two pregnant ewes delivered nor­mal lambs, while the 3^rd ewe was aborted one month after vaccination. RVF virus was isolated from different organs of the aborted foetus. No significant changes were found in total protein, Serum Glutamic Oxalo­acetic Transaminase (GOT) and Serum Pyrovic Transaminase (GPT) than values as compared with non-vaccinated control animals. However, there was significant decrease in albumin value and significant increase in glob­ulin value than in control animals. The neutralizing antibodies were still detectable at protective level till 36 months post-vaccination and the peak was reached at the 3^rd month post-vaccination. The immunoglobu­lins as detected by Enzyme Linked lmmunosorbent Assay (ELISA) were recorded as optical density reading and the results were correlated with those obtained by Serum Neutralization Test (SNT).