The periodontal abscess is localised purulent inflammation of the periodontal tissues and it is third most frequent dental emergency. 2 main etiologies should be distinguished: those related to a preexisting periodontal pocket and impactation of foreign objects and factor altering root morphology or root integrity.The diagnosis should take into account the differential diagnostic possibilities described in the dental literature.The microflora related with periodontal abscess is complex, dominated by G- strict anaerobe rods.It does not to be specific, but known periodontal pathogens such as Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum are the most prevalent bacterial species. A tooth suffering from a periodontal abscess has a worse prognosis and is at a higher risk of being lost. The periodontal abscess is the main reason for tooth extraction. 3 therapeutic approaches have been discussed, including: dreinage and debridment, systemic antibiotics with or without other treatments and periodontal surgery procedures.The localisation of the abscess and the possibility of obtaining dreinage are essential consideration for successful treatment. Antibiotics should be prescribed in case of general symptoms or if complications can be suspected. The addition of systemic antibiotics to the treatment is not well defined issue. The duration of the antibiotic therapy is also a matter of discussion. Some authors have recommended shorter antibiotic regimes. Penicillin has traditionally been the drug of choice in the treatment of odontogenic abscesses. Metronidasole are useful in infections involving betalactamase producing strains. Proper mechanical debridment and local antisptic irrigation should be carried out after resolution of the acute inflammatory phase. The combination of incision and dreinage with the systemic administration of penicillins has be considered often succesful.In the treatment of chronic periodontal abscesses, surgical therapy has been indicated with a surgical flaps.The main objective of the therapy is to eliminate the remaining calculus and obtain dreinage at the same time.