The effective treatment of whooping cough directly depends of early diagnostics. The polymerase chain reaction diagnostic is the most perspective diagnostic technique. The kit of reagents is developed to diagnose whooping cough, parapertussis and bronchosepticosis with polymerase chain reaction. The evaluation of its analytical characteristics was carried out. The sensitivity made 1 x 103 of genome equivalents per 1 ml of sample (the sorption technique of DNA extraction was applied) and 5 x 102 of genome equivalents per 1 ml (the precipitation technique of DNA extraction was used). The specificity of test in the framework of analyzed panel of strains and isolates of microorganisms made 100%. The diagnostic sensitivity of analysis exceeded the sensitivity of bacteriological analysis up to 20 times. The application of this kit of reagents permits to detect and to differentiate DNA of agent of whooping cough, parapertussis during one working day already at the beginning of catarrhal period of disease and up to 18th day from the moment of cough appearance. In perspective, this process creates an opportunity to apply timely the specific therapy. The specter of agents of acute respiratory diseases brining on acute prolonged cough in children who were directed to bacteriological analysis to confirm whooping cough is investigated.