It should be noted that flora such as anaerobic strepto-cocci, intestinal sticks, clostridia causing aerobic gangreneis characterized by the absence of purulent exudate and ne-crosis of soft tissues in the foci of inflammation.The article presents the clinical case of purulent-necroticcellulitis of the floor of the mouth caused by aerobic micro-organisms. Patient M.E. A 79-year-old man was admitted tothe emergency medicine department of the clinic with a diag-nosis of: cellulitis of the floor of the mouth.Objective examination: Infiltration of the soft tissues ofthe oral cavity spread to the chin, both submandibular andsublingual areas, however the inflammatory process was lo-calized predominantly in the lower floor tissues of the oralcavity and mainly on the left side. Extensive necrotic areawas observed in the chin area, which spread to the left sideof the jaw area.The necrotic tissue mass included the skin, subcutane-ous fat, platysma, subcutaneous connective tissue and par-tially the deep muscles of the neck. The patient underwentnecrectomy, in addition to opening and draining the regionsof the oral cavity.An appropriate course of antimicrobial, antihistamine,detoxication, analgesic was prescribed, involving immuno-modulatory drugs. Wounds were routinely repaired with pro-teolytic enzymes, antiseptics, and mechanical removal ofnewly formed necrotic sites. The patient was discharged fromthe clinic in an improved condition for outpatient treatment.