Statement of the Problem: Propionibacterium acnes as been identified as a possible player in bony pathology f the oral cavity. Propionibacterium acnes (P. acnes) is a ram positive, non–spore-forming anaerobic bacillus usully found in the sebaceous glands of the skin. It is a ember of the cutaneous flora, and is considered a comensal organism, but may also by found in the conjunctiva, xternal ear canal, mouth, upper respiratory tract, and ntestine, as well as the oral cavity. Although P. acnes is a ember of the normal skin commensal bacterial flora, it lays a critical role in the development of inflammatory cne when it overgrows and colonizes the pilosebaceous nit. It has been associated with multiple pathologies and lthough it is primarily the causative agent in acne vularis, it has been linked to endophthalmitis, endocardiis, prosthetic hip infection, sciatica, prostatic inflammaion and osteomyelitis. P. acnes is known for its presence n sarcoidosis, a systemic granulomatous condition here it has been the primary bacterium isolated from arcoid lesions. P. acnes is already well associated with umerous post operative bone lesions, most notably, in pine and prosthetic joint replacement surgeries. In hese cases, the organism is primarily thought to be ontracted from the skin as an opportunistic pathogen of he normal skin flora. Recently, Propionibacterium speies have also been implicated in endodontic infections. iqueira Jr et al isolated Propionibacterium propionicus rom persistent root canal infections using PCR, linking he species to periradicular pathology. It is, therefore, robable that Propionibacterium species may be inolved in other forms of bony pathology involving the aw. Materials and Methods: A retrospective study on the ole of P. acnes in its potential as an opportunistic nfection of the oral cavity. Results: In this study, we expand on recent evidence inking P. acnes to oral pathology as an opportunistic ral pathogen. We believe to have the first case of P. cnes isolated from a bony sequestrum of the mandible. Conclusions: With the recent extension of P. acnes involvment in bony pathology and endodontic infections, it is plausible that the organism may have an opportunistic role in lesions of the jaw.