The microbic pattern of osteomyelitic foci were analyzed in patients with chronic osteomyelitis on the AB Expression Analyzer by the 'BioMerieux" anaerobic cultivation and identification system (France). The osteomyelitis-focus microcenosis was shown to be of the mixed anaerobic-aerobic nature. Anaerobic microorganisms were isolated in 65.4% of examined patients and made 34% of the isolated bacterial cultures, which is indicative of an important role of anaerobes in the development and persistence of the purulent-inflammatory process in chronic osteomyelitis. Thus, it is feasible to prescribe the antibacterial drugs, which are active in respect to both aerobic and anaerobic bacteria.