Chlamydophila abortus is one of the most important causative agents of enzootic abortion and other chlamydial infections of sheep and goats. The presence of specific serum antibodies to Chlamydophila abortus was studied in sheep and goats breeding in the Slovak Republic by the complement fixation test. 22,040 sheep and goats were examined during 5 years. Specific anti-Ch. abortus antibodies were found in 2,360 out of 20,878 sheep sera examined (11.7%), and in 85 out of 1,162 examined goats (7.7%). The occurrence of antichlamydial antibodies indicates the importance of performing screening examinations in commercial breeding with the aim of reducing the spread of this disease between animals, and also interrupting the spread and transmission from animals to human.