Clinical findings in cows of seven farms with a frequent occurrence of birth canal inflammations were matched against results of serological and direct immunofluorescence tests for Chlamydia sp. infection. Normal clinical picture, weak to moderate and serious inflammations were found in 16.1%, 46.7% and 37.2% of the 205 examined cows, respectively. The results of micro CFT were negative in 32.7% and titres 1:5, 1:10, 1:20, and 1: > or = 40 were found in 8.7%, 38.0%, 12.3%, and 8.3%, respectively. Direct immunofluorescence test of cervical swabs, using the Progen Biotechnic GmbH set, was negative in 29.1% and clearly positive in 34.7% of the tested cows. The rest was animals in which sporadic elementary bodies were seen. The significance of the findings is discussed and the necessity to test Chlamydia infections in herds affected by frequent and/or chronic inflammations of genital organs is stressed. Evidence of the transmission of Chlamydia infection by contaminated semen is presented.