The authors describe the first experience with the detection of DNA of the periodontal pathogenic bacteria inducing odontogenic inflammation by means of polymerase chain reaction (PCR). The objective of the study was to estimate the effectiveness of the molecular-genetic method for diagnostics of the odontogenic inflammatory processes in the maxillofacial region with the use of various reactant kits. Material and methods. Suppurative exudate obtained from 32 patients presenting with odontogenic phlegmonas at the age varying from 18 to 56 years was investigated using two variants of diagnostic systems (MultiDent-5 and Micro-Ident plus). Results. It was shown that the reactant kits for PCR diagnostics used in the present study made it possible to determine the species composition of periodontal microflora within 24 hours after delivery of urgent care. The spectrum of the 1st and 2nd order periodontal pathogenic microbial species allegedly playing the role in the development of odontogenic inflammation has been identified.