Odontogenic infections are usually locally confined, self-limiting processes. However, under certain circumstances, they may break through the bony, muscular, and mucosal barriers and spread into contiguous fascial spaces or planes far from the initial site of involvement, resulting in severe life-threatening complications, such as retropharyngeal spread, suppurative mediastinal extension, airway obstruction, pleuropulmonary suppuration, and hematogenous dissemination to distant organs. The mortality arte for mediastinitis from odontogenic infection ranges from 40% to 60%. Therefore rapid evalution and treatment is essential with a combination of life support, antibiotic therapy, and surgical intervention. Recently, we experienced three cases of retropharyngeal and mediastinal abscesses secondary to odonogenic infections. In all patients, early diagnosis was possible by CT scanning and physical examination. The prognosis was good in all patients by using urgent aggressive surgical and antibiotic therapy.