In order to exclude the role of bulls used in artificial insemination in venereal transmission of chlamydiae in cattle in Syria, a total of 45 Cryopreserved bull semen samples collected from bulls in production period. Also, 15 fecal samples collected from calves selected for the porpose of artificial insemination were included. The samples were examined by polymerase chain reaction (PCR) after DNA extraction from these samples. The test were repeated sex months later. The results show that all samples were negative by PCR for the presence of Chlamydia and Chlamydophila species. In conclusion, the fail in detection of chlamydiae in bulls semen suggests that these bulls would not play a role in semen born disease of chlamydiae.