The aim of the study was to determine the seroprevalance of Chlamydophila abortus in aborting ewes and cattle in the Kars province in the north-eastern part of Turkey. Thirty sheep flocks and 26 herds of dairy cattle out of 4 districts in the province were examined by ELISA. For this purpose, abortion cases of 236 sheep and 192 cows of different breeds and age were investigated serologically during lambing and calving season. Subsequently, the rate of abortion in ewes and cows were 10.25% (236/2302) and 28.23% (192/680), respectively. Antibodies against C ahortus were found in 46.66% (14/30) of sheep flocks and 26.92% (7/26) cattle herds examined. In the study, 13.98% (33/236) of aborted sheep and 8.33% (16/192) of cattle were positive for antibodies specific to C. abortus. Seroprevalence of C. abortus in sheep and cattle ranged from 5.40 to 18.29% and 4.76 to 12.67%, respectively. In conclusion, C. abortus causes abortion in both sheep and dairy cattle in the north-eastern part of Turkey. It is recommended that seropositive animals should be eliminated from flocks and herds. An appropriate vaccine against C abortus should also be applied for ewes and cows to reduce the incidences of abortion.