Background. Improvement of control methods of treatment of mycoplasma infection in children with bronchial asthma. Methods. 52 children from 1 to 4 years old with bronchial asthma who had mycoplasma antigens in the blood were examined before treatment of mycoplasma infection, 15 patients were examined in 1,5 months after treatment. Reaction of aggregate-hemagglutination, immunofluorescence assay and the reaction of the polymerase chain reaction (PCR) were used for detection of mycoplasmas’ antigens and DNA. Results. In reaction of aggregate-hemagglutination Mycoplasma pneumoniae (Mpn) was detected in 65,4% of patients, Mycoplasma hominis (Mh) — in 32,7%, Ureaplasma urealyticum — in 50%, Mycoplasma arthritidis — in 46,2%, Mycoplasma fermentrans — in 46,2%. In more detail, we investigated Mpn and Mh. Antigens of Mpn and Mh were detected in serum significantly frequently than DNA by PCR. DNA in structure of circulating immune complexes (CIC) was detected more often than in free state. After treatment by azithromycin the number of positive tests on antigens and DNA in free state and in structure of CIC decreased. In most cases DNA found in serum of blood in free state and in structure of CIC belongs to persistent living cells of mycoplasma. Conclusion. Empowering diagnosis of mycoplasma infections in asthma in children allows to base a comprehensive approach to laboratory diagnosis, monitor treatment, predict disease course.