This study was conducted on two flocks of sheep (East - Friesian Breed) suffering from outbreak of Enzootic Ovine Abortion (EOA) in North Palestine. The clinical findings in ewes were abortion in the second half of gestation period, mummified, dead fetuses and stillbirth, pyrexia, anorexia, dark red or clay colored vaginal discharges and retention of placentas. The causative agent was isolated on yolk sac of embryonated hen egg 6-8 days old from aborted fetuses, vaginal discharges, placentas and identified by detection of elementary bodies in primary impression smears prepared from aborted fetuses, vaginal discharges, placentas and Chlamydiophilia abortus antigen by "sandwich method" Enzyme linked Immunosorbent Assay (ELISA). The disease was controlled by using three successive doses of long acting oxy tetracycline intramuscularly at a dose rate 20 mg\kg body weight.