This study was carried out on 180 pregnant ewes located at Ras Sedr research station - desert research center, from 2003 to 2005. Twenty five cases of abortion were recorded and examined serologically by complement fixation test (CFT). 17 (68%) out of these 25, showed positive results against Chlamydophila abortus and 3(15%) out of 20 apparently healthy pregnant ewes were serologically positive. Due to the fact that both clinical signs and pathological findings are not specific in case of chlamydial infection and also due to the fact that CFT is accompanied by false positive reactions due to cross reactivity between chlamydial species, five samples from serologically positive aborted dams were subjected to polymerase chain reaction (PCR). They revealed positive results for Chlamydophila abortus at 119 bp. Therefore, PCR is proven to be reliable, rapid and specific diagnostic technique in the
diagnosis of chlamydial infection.